Merge lp:~widelands-dev/widelands/dynamic_tribe_loading into lp:widelands

[GunChleoc]

Dynamic loading of the tribes' map objects and of custom scenario tribe objects:

- Simplified tribes/init.lua: The tribe directory is now walked automatically, without the need of manually getting the load order right. Missing prerequisite map objects are parsed during postload.

- If scripting/tribes/init.lua exists in a map, run it to load custom tribe objects when starting a new scenario. So far, only buildings are supported via a new function Tribes::add_custom_building{table} in lua_root.

Reworked the tribe loading to make it more moddable. I'd like this branch to have priority, because it affects hessenfarmer's work on the Empire 4 scenario.

An adjusted version of the new scenario for testing is available in https://code.launchpad.net/~widelands-dev/widelands/dynamic_tribe_loading_datadir

[bunnybot (widelandsofficial)]

Continuous integration builds have changed state:

Travis build 2568. State: failed. Details: https://travis-ci.org/widelands/widelands/builds/265695435.
Appveyor build 2390. State: success. Details: https://ci.appveyor.com/project/widelands-dev/widelands/build/_widelands_dev_widelands_dynamic_tribe_loading-2390.

[bunnybot (widelandsofficial)]

Continuous integration builds have changed state:

Travis build 2572. State: passed. Details: https://travis-ci.org/widelands/widelands/builds/265868340.
Appveyor build 2394. State: success. Details: https://ci.appveyor.com/project/widelands-dev/widelands/build/_widelands_dev_widelands_dynamic_tribe_loading-2394.

[bunnybot (widelandsofficial)]

Continuous integration builds have changed state:

Travis build 2615. State: errored. Details: https://travis-ci.org/widelands/widelands/builds/269986493.
Appveyor build 2437. State: success. Details: https://ci.appveyor.com/project/widelands-dev/widelands/build/_widelands_dev_widelands_dynamic_tribe_loading-2437.

[bunnybot (widelandsofficial)]

Continuous integration builds have changed state:

Travis build 2646. State: passed. Details: https://travis-ci.org/widelands/widelands/builds/271368683.
Appveyor build 2468. State: success. Details: https://ci.appveyor.com/project/widelands-dev/widelands/build/_widelands_dev_widelands_dynamic_tribe_loading-2468.

[SirVer (sirver)]

I think this is a cool feature, thanks for working on this.

I am a bit unhappy about the postload() design approach, but that is not the fault of this branch. We are constructing partially initialized objects right and left and that gets pretty confusing - when is which data valid? I think it would be better to collecting all inter-object dependencies while loading the objects into a collection that is passed around to the loading functions. Later, they are all resolved at one point and missing objects can be reported then. What do you think? Do you want to try this in this branch or defer?

review: Needs Fixing

[GunChleoc (gunchleoc)]

I'd definitely want to try this in a different branch, as I expect the changes to be big.

I also can't deal with all your suggestions below in a teeny tiny VM window, so finishing this branch will have to wait until next month. It would still be great though if you had time for more reviews while I'm gone, so that I can start proposing more of my branches for merge when I get back home.

[GunChleoc (gunchleoc)]

I have added comments to the things that I plan not to change - will need to go through the rest in detail.

[GunChleoc (gunchleoc)]

Making the Lua code prettier does not work - it will give me a crash with unknown function.

[bunnybot (widelandsofficial)]

Continuous integration builds have changed state:

Travis build 2739. State: failed. Details: https://travis-ci.org/widelands/widelands/builds/296435108.
Appveyor build 2551. State: failed. Details: https://ci.appveyor.com/project/widelands-dev/widelands/build/_widelands_dev_widelands_dynamic_tribe_loading-2551.

[GunChleoc (gunchleoc)]

This should be ready now.

I added the remaining comments as NOCOM to the code for easier review and addressed all the rest. I have answered in the code.

For full testing, take the datadir from

https://code.launchpad.net/~widelands-dev/widelands/dynamic_tribe_loading_datadir

And start Empire Scenario 4.

review: Needs Resubmitting

[bunnybot (widelandsofficial)]

Continuous integration builds have changed state:

Travis build 2748. State: errored. Details: https://travis-ci.org/widelands/widelands/builds/296945317.
Appveyor build 2560. State: success. Details: https://ci.appveyor.com/project/widelands-dev/widelands/build/_widelands_dev_widelands_dynamic_tribe_loading-2560.

[SirVer (sirver)]

Reviewed and tested. The new scenario is a lot of fun!

@bunnybot merge

review: Approve

[bunnybot (widelandsofficial)]

Refusing to merge, since Travis is not green. Use @bunnybot merge force for merging anyways.

Travis build 2748. State: errored. Details: https://travis-ci.org/widelands/widelands/builds/296945317.

[GunChleoc (gunchleoc)]

Thanks for the review!

@bunnybot merge

[bunnybot (widelandsofficial)]

Refusing to merge, since Travis is not green. Use @bunnybot merge force for merging anyways.

Travis build 2780. State: errored. Details: https://travis-ci.org/widelands/widelands/builds/298994801.

[GunChleoc (gunchleoc)]

r8439 broke the test suite.

[SirVer (sirver)]

Hooray for testing!

[GunChleoc (gunchleoc)]

Indeed! Now I need to find out where the extra 200 builders come from :P

[hessenfarmer (stephan-lutz)]

As soon as this branch will be in trunk I will adapt Mission 4 data according to the changes in dynamic_tribe_loading_datadir and ask for merge then. Does this sound ok? Or should we do this in different order?

[GunChleoc (gunchleoc)]

Sounds good to me.

[GunChleoc (gunchleoc)]

I have been fiddling with a test branch https://code.launchpad.net/~widelands-dev/widelands/dynamic_tribe_loading_test and I have found the change that broke it:

http://bazaar.launchpad.net/~widelands-dev/widelands/dynamic_tribe_loading_test/view/head:/src/logic/map_objects/tribes/worker_descr.cc#L72

The problem is that I have no idea why, so I'm not comfortable with merging this. Maybe I have uncovered an underlying bug, or I have done something stupid that I'm not seeing.

Does anybody have any idea?

review: Needs Fixing

[GunChleoc (gunchleoc)]

I'm giving up on this for now, so I have created a new branch that contains only the bits that the scenario editors need to continue their work:

https://code.launchpad.net/~widelands-dev/widelands/add_custom_building/+merge/334062

[SirVer (sirver)]

I cannot look into this right now, but here is what I usually do in such scenarios: I try to pull out independent changes from a branch into always smaller patches and check them in independently. Eventually the problem surfaces more clearly.

[GunChleoc (gunchleoc)]

This is exactly what I have done. The problem is that the changed line should not cause a segfault at all, so I'm stumped.

=== modified file 'data/tribes/init.lua'
--- data/tribes/init.lua	2017-12-13 07:47:36 +0000
+++ data/tribes/init.lua	2018-03-01 07:56:38 +0000
@@ -11,12 +11,33 @@
 --
 -- Basic load order (first wares, then immovables etc.) is important,
 -- because checks will be made in C++.
--- Also, enhanced/upgraded units need to come before their basic units.
 --
 
 tribes = wl.Tribes()
 include "scripting/mapobjects.lua"
 
+-- Load all init.lua files in the given table of directory names
+function load_directories(directories)
+   -- Helper function to check for file name endings
+   function string.ends(haystack, needle)
+      return needle == '' or string.sub(haystack, -string.len(needle)) == needle
+   end
+
+   while #directories > 0 do
+      local filepath = directories[1]
+      table.remove(directories, 1)
+      if path.is_directory(filepath) then
+         for idx, listed_path in ipairs(path.list_directory(filepath)) do
+            if path.is_directory(listed_path) then
+               table.insert(directories, listed_path)
+            elseif string.ends(listed_path , "init.lua") then
+               include(listed_path)
+            end
+         end
+      end
+   end
+end
+
 print("┏━ Running Lua for tribes:")
 
 print_loading_message("┗━ took", function()
@@ -25,9 +46,7 @@
    -- ===================================
 
    print_loading_message("┃    Ships", function()
-      include "tribes/ships/atlanteans/init.lua"
-      include "tribes/ships/barbarians/init.lua"
-      include "tribes/ships/empire/init.lua"
+      load_directories({"tribes/ships"})
    end)
 
    -- ===================================
@@ -35,91 +54,7 @@
    -- ===================================
 
    print_loading_message("┃    Wares", function()
-      include "tribes/wares/armor/init.lua"
-      include "tribes/wares/armor_chain/init.lua"
-      include "tribes/wares/armor_gilded/init.lua"
-      include "tribes/wares/armor_helmet/init.lua"
-      include "tribes/wares/ax/init.lua"
-      include "tribes/wares/ax_battle/init.lua"
-      include "tribes/wares/ax_broad/init.lua"
-      include "tribes/wares/ax_bronze/init.lua"
-      include "tribes/wares/ax_sharp/init.lua"
-      include "tribes/wares/ax_warriors/init.lua"
-      include "tribes/wares/basket/init.lua"
-      include "tribes/wares/beer/init.lua"
-      include "tribes/wares/beer_strong/init.lua"
-      include "tribes/wares/blackroot/init.lua"
-      include "tribes/wares/blackroot_flour/init.lua"
-      include "tribes/wares/blackwood/init.lua"
-      include "tribes/wares/bread_atlanteans/init.lua"
-      include "tribes/wares/bread_barbarians/init.lua"
-      include "tribes/wares/bread_empire/init.lua"
-      include "tribes/wares/bread_paddle/init.lua"
-      include "tribes/wares/buckets/init.lua"
-      include "tribes/wares/cloth/init.lua"
-      include "tribes/wares/coal/init.lua"
-      include "tribes/wares/corn/init.lua"
-      include "tribes/wares/cornmeal/init.lua"
-      include "tribes/wares/diamond/init.lua"
-      include "tribes/wares/felling_ax/init.lua"
-      include "tribes/wares/fire_tongs/init.lua"
-      include "tribes/wares/fish/init.lua"
-      include "tribes/wares/fishing_net/init.lua"
-      include "tribes/wares/fishing_rod/init.lua"
-      include "tribes/wares/flour/init.lua"
-      include "tribes/wares/gold/init.lua"
-      include "tribes/wares/gold_ore/init.lua"
-      include "tribes/wares/gold_thread/init.lua"
-      include "tribes/wares/granite/init.lua"
-      include "tribes/wares/grape/init.lua"
-      include "tribes/wares/grout/init.lua"
-      include "tribes/wares/hammer/init.lua"
-      include "tribes/wares/helmet/init.lua"
-      include "tribes/wares/helmet_mask/init.lua"
-      include "tribes/wares/helmet_warhelm/init.lua"
-      include "tribes/wares/hook_pole/init.lua"
-      include "tribes/wares/hunting_bow/init.lua"
-      include "tribes/wares/hunting_spear/init.lua"
-      include "tribes/wares/iron/init.lua"
-      include "tribes/wares/iron_ore/init.lua"
-      include "tribes/wares/kitchen_tools/init.lua"
-      include "tribes/wares/log/init.lua"
-      include "tribes/wares/marble/init.lua"
-      include "tribes/wares/marble_column/init.lua"
-      include "tribes/wares/meal/init.lua"
-      include "tribes/wares/meat/init.lua"
-      include "tribes/wares/milking_tongs/init.lua"
-      include "tribes/wares/pick/init.lua"
-      include "tribes/wares/planks/init.lua"
-      include "tribes/wares/quartz/init.lua"
-      include "tribes/wares/ration/init.lua"
-      include "tribes/wares/saw/init.lua"
-      include "tribes/wares/scythe/init.lua"
-      include "tribes/wares/shield_advanced/init.lua"
-      include "tribes/wares/shield_steel/init.lua"
-      include "tribes/wares/shovel/init.lua"
-      include "tribes/wares/smoked_fish/init.lua"
-      include "tribes/wares/smoked_meat/init.lua"
-      include "tribes/wares/snack/init.lua"
-      include "tribes/wares/spear/init.lua"
-      include "tribes/wares/spear_advanced/init.lua"
-      include "tribes/wares/spear_heavy/init.lua"
-      include "tribes/wares/spear_war/init.lua"
-      include "tribes/wares/spear_wooden/init.lua"
-      include "tribes/wares/spidercloth/init.lua"
-      include "tribes/wares/spider_silk/init.lua"
-      include "tribes/wares/tabard/init.lua"
-      include "tribes/wares/tabard_golden/init.lua"
-      include "tribes/wares/thatch_reed/init.lua"
-      include "tribes/wares/trident_double/init.lua"
-      include "tribes/wares/trident_heavy_double/init.lua"
-      include "tribes/wares/trident_light/init.lua"
-      include "tribes/wares/trident_long/init.lua"
-      include "tribes/wares/trident_steel/init.lua"
-      include "tribes/wares/water/init.lua"
-      include "tribes/wares/wheat/init.lua"
-      include "tribes/wares/wine/init.lua"
-      include "tribes/wares/wool/init.lua"
+      load_directories({"tribes/wares"})
    end)
 
    -- ===================================
@@ -127,44 +62,7 @@
    -- ===================================
 
    print_loading_message("┃    Immovables", function()
-      include "tribes/immovables/ashes/init.lua"
-      include "tribes/immovables/blackrootfield_harvested/init.lua"
-      include "tribes/immovables/blackrootfield_medium/init.lua"
-      include "tribes/immovables/blackrootfield_ripe/init.lua"
-      include "tribes/immovables/blackrootfield_small/init.lua"
-      include "tribes/immovables/blackrootfield_tiny/init.lua"
-      include "tribes/immovables/cornfield_harvested/init.lua"
-      include "tribes/immovables/cornfield_medium/init.lua"
-      include "tribes/immovables/cornfield_ripe/init.lua"
-      include "tribes/immovables/cornfield_small/init.lua"
-      include "tribes/immovables/cornfield_tiny/init.lua"
-      include "tribes/immovables/destroyed_building/init.lua"
-      include "tribes/immovables/field_harvested/init.lua"
-      include "tribes/immovables/field_medium/init.lua"
-      include "tribes/immovables/field_ripe/init.lua"
-      include "tribes/immovables/field_small/init.lua"
-      include "tribes/immovables/field_tiny/init.lua"
-      include "tribes/immovables/grapevine_medium/init.lua"
-      include "tribes/immovables/grapevine_ripe/init.lua"
-      include "tribes/immovables/grapevine_small/init.lua"
-      include "tribes/immovables/grapevine_tiny/init.lua"
-      include "tribes/immovables/reed_medium/init.lua"
-      include "tribes/immovables/reed_ripe/init.lua"
-      include "tribes/immovables/reed_small/init.lua"
-      include "tribes/immovables/reed_tiny/init.lua"
-      include "tribes/immovables/resi_coal1/init.lua"
-      include "tribes/immovables/resi_coal2/init.lua"
-      include "tribes/immovables/resi_gold1/init.lua"
-      include "tribes/immovables/resi_gold2/init.lua"
-      include "tribes/immovables/resi_iron1/init.lua"
-      include "tribes/immovables/resi_iron2/init.lua"
-      include "tribes/immovables/resi_none/init.lua"
-      include "tribes/immovables/resi_stones1/init.lua"
-      include "tribes/immovables/resi_stones2/init.lua"
-      include "tribes/immovables/resi_water1/init.lua"
-      include "tribes/immovables/shipconstruction_atlanteans/init.lua"
-      include "tribes/immovables/shipconstruction_barbarians/init.lua"
-      include "tribes/immovables/shipconstruction_empire/init.lua"
+      load_directories({"tribes/immovables"})
    end)
 
    -- ===================================
@@ -172,103 +70,7 @@
    -- ===================================
 
    print_loading_message("┃    Workers", function()
-      include "tribes/workers/atlanteans/carrier/init.lua"
-      include "tribes/workers/atlanteans/armorsmith/init.lua"
-      include "tribes/workers/atlanteans/baker/init.lua"
-      include "tribes/workers/atlanteans/blackroot_farmer/init.lua"
-      include "tribes/workers/atlanteans/builder/init.lua"
-      include "tribes/workers/atlanteans/charcoal_burner/init.lua"
-      include "tribes/workers/atlanteans/farmer/init.lua"
-      include "tribes/workers/atlanteans/fishbreeder/init.lua"
-      include "tribes/workers/atlanteans/fisher/init.lua"
-      include "tribes/workers/atlanteans/forester/init.lua"
-      include "tribes/workers/atlanteans/geologist/init.lua"
-      include "tribes/workers/atlanteans/horse/init.lua"
-      include "tribes/workers/atlanteans/horsebreeder/init.lua"
-      include "tribes/workers/atlanteans/hunter/init.lua"
-      include "tribes/workers/atlanteans/miller/init.lua"
-      include "tribes/workers/atlanteans/miner/init.lua"
-      include "tribes/workers/atlanteans/recruit/init.lua"
-      include "tribes/workers/atlanteans/sawyer/init.lua"
-      include "tribes/workers/atlanteans/scout/init.lua"
-      include "tribes/workers/atlanteans/shipwright/init.lua"
-      include "tribes/workers/atlanteans/smelter/init.lua"
-      include "tribes/workers/atlanteans/smoker/init.lua"
-      include "tribes/workers/atlanteans/soldier/init.lua"
-      include "tribes/workers/atlanteans/spiderbreeder/init.lua"
-      include "tribes/workers/atlanteans/stonecutter/init.lua"
-      include "tribes/workers/atlanteans/toolsmith/init.lua"
-      include "tribes/workers/atlanteans/trainer/init.lua"
-      include "tribes/workers/atlanteans/weaponsmith/init.lua"
-      include "tribes/workers/atlanteans/weaver/init.lua"
-      include "tribes/workers/atlanteans/woodcutter/init.lua"
-
-      include "tribes/workers/barbarians/carrier/init.lua"
-      include "tribes/workers/barbarians/baker/init.lua"
-      include "tribes/workers/barbarians/blacksmith_master/init.lua"
-      include "tribes/workers/barbarians/blacksmith/init.lua"
-      include "tribes/workers/barbarians/brewer_master/init.lua"
-      include "tribes/workers/barbarians/brewer/init.lua"
-      include "tribes/workers/barbarians/builder/init.lua"
-      include "tribes/workers/barbarians/cattlebreeder/init.lua"
-      include "tribes/workers/barbarians/charcoal_burner/init.lua"
-      include "tribes/workers/barbarians/farmer/init.lua"
-      include "tribes/workers/barbarians/fisher/init.lua"
-      include "tribes/workers/barbarians/gamekeeper/init.lua"
-      include "tribes/workers/barbarians/gardener/init.lua"
-      include "tribes/workers/barbarians/geologist/init.lua"
-      include "tribes/workers/barbarians/helmsmith/init.lua"
-      include "tribes/workers/barbarians/hunter/init.lua"
-      include "tribes/workers/barbarians/innkeeper/init.lua"
-      include "tribes/workers/barbarians/lime_burner/init.lua"
-      include "tribes/workers/barbarians/lumberjack/init.lua"
-      include "tribes/workers/barbarians/miner_master/init.lua"
-      include "tribes/workers/barbarians/miner_chief/init.lua"
-      include "tribes/workers/barbarians/miner/init.lua"
-      include "tribes/workers/barbarians/ox/init.lua"
-      include "tribes/workers/barbarians/ranger/init.lua"
-      include "tribes/workers/barbarians/recruit/init.lua"
-      include "tribes/workers/barbarians/scout/init.lua"
-      include "tribes/workers/barbarians/shipwright/init.lua"
-      include "tribes/workers/barbarians/smelter/init.lua"
-      include "tribes/workers/barbarians/soldier/init.lua"
-      include "tribes/workers/barbarians/stonemason/init.lua"
-      include "tribes/workers/barbarians/trainer/init.lua"
-      include "tribes/workers/barbarians/weaver/init.lua"
-
-      include "tribes/workers/empire/carrier/init.lua"
-      include "tribes/workers/empire/armorsmith/init.lua"
-      include "tribes/workers/empire/baker/init.lua"
-      include "tribes/workers/empire/brewer/init.lua"
-      include "tribes/workers/empire/builder/init.lua"
-      include "tribes/workers/empire/carpenter/init.lua"
-      include "tribes/workers/empire/charcoal_burner/init.lua"
-      include "tribes/workers/empire/donkey/init.lua"
-      include "tribes/workers/empire/donkeybreeder/init.lua"
-      include "tribes/workers/empire/farmer/init.lua"
-      include "tribes/workers/empire/fisher/init.lua"
-      include "tribes/workers/empire/forester/init.lua"
-      include "tribes/workers/empire/geologist/init.lua"
-      include "tribes/workers/empire/hunter/init.lua"
-      include "tribes/workers/empire/innkeeper/init.lua"
-      include "tribes/workers/empire/lumberjack/init.lua"
-      include "tribes/workers/empire/miller/init.lua"
-      include "tribes/workers/empire/miner_master/init.lua"
-      include "tribes/workers/empire/miner/init.lua"
-      include "tribes/workers/empire/pigbreeder/init.lua"
-      include "tribes/workers/empire/recruit/init.lua"
-      include "tribes/workers/empire/scout/init.lua"
-      include "tribes/workers/empire/shepherd/init.lua"
-      include "tribes/workers/empire/shipwright/init.lua"
-      include "tribes/workers/empire/smelter/init.lua"
-      include "tribes/workers/empire/soldier/init.lua"
-      include "tribes/workers/empire/stonemason/init.lua"
-      include "tribes/workers/empire/toolsmith/init.lua"
-      include "tribes/workers/empire/trainer/init.lua"
-      include "tribes/workers/empire/vinefarmer/init.lua"
-      include "tribes/workers/empire/vintner/init.lua"
-      include "tribes/workers/empire/weaponsmith/init.lua"
-      include "tribes/workers/empire/weaver/init.lua"
+      load_directories({"tribes/workers"})
    end)
 
    -- ===================================
@@ -276,17 +78,7 @@
    -- ===================================
 
    print_loading_message("┃    Warehouses", function()
-      include "tribes/buildings/warehouses/atlanteans/headquarters/init.lua"
-      include "tribes/buildings/warehouses/atlanteans/port/init.lua"
-      include "tribes/buildings/warehouses/atlanteans/warehouse/init.lua"
-      include "tribes/buildings/warehouses/barbarians/headquarters/init.lua"
-      include "tribes/buildings/warehouses/barbarians/headquarters_interim/init.lua"
-      include "tribes/buildings/warehouses/barbarians/port/init.lua"
-      include "tribes/buildings/warehouses/barbarians/warehouse/init.lua"
-      include "tribes/buildings/warehouses/empire/headquarters/init.lua"
-      include "tribes/buildings/warehouses/empire/headquarters_shipwreck/init.lua"
-      include "tribes/buildings/warehouses/empire/port/init.lua"
-      include "tribes/buildings/warehouses/empire/warehouse/init.lua"
+      load_directories({"tribes/buildings/warehouses"})
    end)
 
    -- ===================================
@@ -294,132 +86,14 @@
    -- ===================================
 
    print_loading_message("┃    Markets", function()
-      include "tribes/buildings/markets/barbarians/market/init.lua"
+      load_directories({"tribes/buildings/markets"})
    end)
    -- ===================================
    --    Productionsites
    -- ===================================
 
    print_loading_message("┃    Productionsites", function()
-      -- Atlanteans small
-      include "tribes/buildings/productionsites/atlanteans/quarry/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/woodcutters_house/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/foresters_house/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/fishers_house/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/fishbreeders_house/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/hunters_house/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/well/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/gold_spinning_mill/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/scouts_house/init.lua"
-      -- Atlanteans medium
-      include "tribes/buildings/productionsites/atlanteans/sawmill/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/smokery/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/mill/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/bakery/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/charcoal_kiln/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/smelting_works/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/shipyard/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/toolsmithy/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/weaponsmithy/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/armorsmithy/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/barracks/init.lua"
-
-      -- Atlanteans big
-      include "tribes/buildings/productionsites/atlanteans/horsefarm/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/farm/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/blackroot_farm/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/spiderfarm/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/weaving_mill/init.lua"
-
-      -- Atlanteans mines
-      include "tribes/buildings/productionsites/atlanteans/crystalmine/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/coalmine/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/ironmine/init.lua"
-      include "tribes/buildings/productionsites/atlanteans/goldmine/init.lua"
-      -- Barbarians small
-      include "tribes/buildings/productionsites/barbarians/quarry/init.lua"
-      include "tribes/buildings/productionsites/barbarians/lumberjacks_hut/init.lua"
-      include "tribes/buildings/productionsites/barbarians/rangers_hut/init.lua"
-      include "tribes/buildings/productionsites/barbarians/fishers_hut/init.lua"
-      include "tribes/buildings/productionsites/barbarians/hunters_hut/init.lua"
-      include "tribes/buildings/productionsites/barbarians/gamekeepers_hut/init.lua"
-      include "tribes/buildings/productionsites/barbarians/well/init.lua"
-      include "tribes/buildings/productionsites/barbarians/scouts_hut/init.lua"
-      -- Barbarians medium
-      include "tribes/buildings/productionsites/barbarians/wood_hardener/init.lua"
-      include "tribes/buildings/productionsites/barbarians/lime_kiln/init.lua"
-      include "tribes/buildings/productionsites/barbarians/reed_yard/init.lua"
-      include "tribes/buildings/productionsites/barbarians/bakery/init.lua"
-      include "tribes/buildings/productionsites/barbarians/brewery/init.lua"
-      include "tribes/buildings/productionsites/barbarians/micro_brewery/init.lua"
-      include "tribes/buildings/productionsites/barbarians/big_inn/init.lua"
-      include "tribes/buildings/productionsites/barbarians/inn/init.lua"
-      include "tribes/buildings/productionsites/barbarians/tavern/init.lua"
-      include "tribes/buildings/productionsites/barbarians/charcoal_kiln/init.lua"
-      include "tribes/buildings/productionsites/barbarians/smelting_works/init.lua"
-      include "tribes/buildings/productionsites/barbarians/shipyard/init.lua"
-      include "tribes/buildings/productionsites/barbarians/warmill/init.lua"
-      include "tribes/buildings/productionsites/barbarians/ax_workshop/init.lua"
-      include "tribes/buildings/productionsites/barbarians/metal_workshop/init.lua"
-      include "tribes/buildings/productionsites/barbarians/barracks/init.lua"
-
-      -- Barbarians big
-      include "tribes/buildings/productionsites/barbarians/cattlefarm/init.lua"
-      include "tribes/buildings/productionsites/barbarians/farm/init.lua"
-      include "tribes/buildings/productionsites/barbarians/weaving_mill/init.lua"
-      include "tribes/buildings/productionsites/barbarians/helmsmithy/init.lua"
-      -- Barbarians mines
-      include "tribes/buildings/productionsites/barbarians/granitemine/init.lua"
-      include "tribes/buildings/productionsites/barbarians/coalmine_deeper/init.lua"
-      include "tribes/buildings/productionsites/barbarians/coalmine_deep/init.lua"
-      include "tribes/buildings/productionsites/barbarians/coalmine/init.lua"
-      include "tribes/buildings/productionsites/barbarians/ironmine_deeper/init.lua"
-      include "tribes/buildings/productionsites/barbarians/ironmine_deep/init.lua"
-      include "tribes/buildings/productionsites/barbarians/ironmine/init.lua"
-      include "tribes/buildings/productionsites/barbarians/goldmine_deeper/init.lua"
-      include "tribes/buildings/productionsites/barbarians/goldmine_deep/init.lua"
-      include "tribes/buildings/productionsites/barbarians/goldmine/init.lua"
-      -- Empire small
-      include "tribes/buildings/productionsites/empire/quarry/init.lua"
-      include "tribes/buildings/productionsites/empire/lumberjacks_house/init.lua"
-      include "tribes/buildings/productionsites/empire/foresters_house/init.lua"
-      include "tribes/buildings/productionsites/empire/fishers_house/init.lua"
-      include "tribes/buildings/productionsites/empire/hunters_house/init.lua"
-      include "tribes/buildings/productionsites/empire/well/init.lua"
-      include "tribes/buildings/productionsites/empire/scouts_house/init.lua"
-      -- Empire medium
-      include "tribes/buildings/productionsites/empire/stonemasons_house/init.lua"
-      include "tribes/buildings/productionsites/empire/sawmill/init.lua"
-      include "tribes/buildings/productionsites/empire/mill/init.lua"
-      include "tribes/buildings/productionsites/empire/bakery/init.lua"
-      include "tribes/buildings/productionsites/empire/brewery/init.lua"
-      include "tribes/buildings/productionsites/empire/vineyard/init.lua"
-      include "tribes/buildings/productionsites/empire/winery/init.lua"
-      include "tribes/buildings/productionsites/empire/inn/init.lua"
-      include "tribes/buildings/productionsites/empire/tavern/init.lua"
-      include "tribes/buildings/productionsites/empire/charcoal_kiln/init.lua"
-      include "tribes/buildings/productionsites/empire/smelting_works/init.lua"
-      include "tribes/buildings/productionsites/empire/shipyard/init.lua"
-      include "tribes/buildings/productionsites/empire/toolsmithy/init.lua"
-      include "tribes/buildings/productionsites/empire/armorsmithy/init.lua"
-      -- Empire big
-      include "tribes/buildings/productionsites/empire/donkeyfarm/init.lua"
-      include "tribes/buildings/productionsites/empire/farm/init.lua"
-      include "tribes/buildings/productionsites/empire/piggery/init.lua"
-      include "tribes/buildings/productionsites/empire/sheepfarm/init.lua"
-      include "tribes/buildings/productionsites/empire/weaving_mill/init.lua"
-      include "tribes/buildings/productionsites/empire/weaponsmithy/init.lua"
-      include "tribes/buildings/productionsites/empire/barracks/init.lua"
-
-      -- Empire mines
-      include "tribes/buildings/productionsites/empire/coalmine_deep/init.lua"
-      include "tribes/buildings/productionsites/empire/coalmine/init.lua"
-      include "tribes/buildings/productionsites/empire/ironmine_deep/init.lua"
-      include "tribes/buildings/productionsites/empire/ironmine/init.lua"
-      include "tribes/buildings/productionsites/empire/marblemine_deep/init.lua"
-      include "tribes/buildings/productionsites/empire/marblemine/init.lua"
-      include "tribes/buildings/productionsites/empire/goldmine_deep/init.lua"
-      include "tribes/buildings/productionsites/empire/goldmine/init.lua"
+      load_directories({"tribes/buildings/productionsites"})
    end)
 
    -- ===================================
@@ -427,13 +101,7 @@
    -- ===================================
 
    print_loading_message("┃    Trainingsites", function()
-      include "tribes/buildings/trainingsites/atlanteans/dungeon/init.lua"
-      include "tribes/buildings/trainingsites/atlanteans/labyrinth/init.lua"
-      include "tribes/buildings/trainingsites/barbarians/battlearena/init.lua"
-      include "tribes/buildings/trainingsites/barbarians/trainingcamp/init.lua"
-      include "tribes/buildings/trainingsites/empire/colosseum/init.lua"
-      include "tribes/buildings/trainingsites/empire/arena/init.lua"
-      include "tribes/buildings/trainingsites/empire/trainingcamp/init.lua"
+      load_directories({"tribes/buildings/trainingsites"})
    end)
 
    -- ===================================
@@ -441,26 +109,7 @@
    -- ===================================
 
    print_loading_message("┃    Militarysites", function()
-      include "tribes/buildings/militarysites/atlanteans/guardhouse/init.lua"
-      include "tribes/buildings/militarysites/atlanteans/guardhall/init.lua"
-      include "tribes/buildings/militarysites/atlanteans/tower_small/init.lua"
-      include "tribes/buildings/militarysites/atlanteans/tower_high/init.lua"
-      include "tribes/buildings/militarysites/atlanteans/tower/init.lua"
-      include "tribes/buildings/militarysites/atlanteans/castle/init.lua"
-
-      include "tribes/buildings/militarysites/barbarians/sentry/init.lua"
-      include "tribes/buildings/militarysites/barbarians/barrier/init.lua"
-      include "tribes/buildings/militarysites/barbarians/tower/init.lua"
-      include "tribes/buildings/militarysites/barbarians/citadel/init.lua"
-      include "tribes/buildings/militarysites/barbarians/fortress/init.lua"
-
-      include "tribes/buildings/militarysites/empire/sentry/init.lua"
-      include "tribes/buildings/militarysites/empire/blockhouse/init.lua"
-      include "tribes/buildings/militarysites/empire/barrier/init.lua"
-      include "tribes/buildings/militarysites/empire/outpost/init.lua"
-      include "tribes/buildings/militarysites/empire/tower/init.lua"
-      include "tribes/buildings/militarysites/empire/castle/init.lua"
-      include "tribes/buildings/militarysites/empire/fortress/init.lua"
+      load_directories({"tribes/buildings/militarysites"})
    end)
 
    -- ===================================
@@ -468,8 +117,7 @@
    -- ===================================
 
    print_loading_message("┃    Partially finished buildings", function()
-      include "tribes/buildings/partially_finished/constructionsite/init.lua"
-      include "tribes/buildings/partially_finished/dismantlesite/init.lua"
+      load_directories({"tribes/buildings/partially_finished"})
    end)
 
    -- ===================================

=== modified file 'src/logic/map_objects/tribes/building.cc'
--- src/logic/map_objects/tribes/building.cc	2018-01-11 11:40:45 +0000
+++ src/logic/map_objects/tribes/building.cc	2018-03-01 07:56:38 +0000
@@ -57,9 +57,9 @@
 BuildingDescr::BuildingDescr(const std::string& init_descname,
                              const MapObjectType init_type,
                              const LuaTable& table,
-                             const EditorGameBase& egbase)
+                             EditorGameBase* egbase)
    : MapObjectDescr(init_type, table.get_string("name"), init_descname, table),
-     egbase_(egbase),
+     egbase_(*egbase),
      buildable_(false),
      size_(BaseImmovable::SMALL),
      mine_(false),
@@ -111,27 +111,11 @@
 
 	if (table.has_key("enhancement")) {
 		const std::string enh = table.get_string("enhancement");
-
 		if (enh == name()) {
 			throw wexception("enhancement to same type");
 		}
-		DescriptionIndex const en_i = egbase_.tribes().building_index(enh);
-		if (egbase_.tribes().building_exists(en_i)) {
-			enhancement_ = en_i;
-
-			//  Merge the enhancements workarea info into this building's
-			//  workarea info.
-			const BuildingDescr* tmp_enhancement = egbase_.tribes().get_building_descr(en_i);
-			for (auto area : tmp_enhancement->workarea_info_) {
-				std::set<std::string>& strs = workarea_info_[area.first];
-				for (std::string str : area.second)
-					strs.insert(str);
-			}
-		} else {
-			throw wexception(
-			   "\"%s\" has not been defined as a building type (wrong declaration order?)",
-			   enh.c_str());
-		}
+		// The advanced building might not have been loaded yet, so we'll do this in postload.
+		egbase->mutable_tribes()->add_mapobject_enhancement({MapObjectType::BUILDING, name(), enh});
 	}
 
 	if (table.has_key("buildcost")) {
@@ -165,6 +149,19 @@
 	}
 }
 
+void BuildingDescr::set_enhances_to(const std::string& enhancement_name) {
+	enhancement_ = egbase_.tribes().safe_building_index(enhancement_name);
+
+	//  Merge the enhancement's workarea info into this building's
+	//  workarea info.
+	for (auto area : egbase_.tribes().get_building_descr(enhancement_)->workarea_info_) {
+		std::set<std::string>& strs = workarea_info_[area.first];
+		for (std::string str : area.second) {
+			strs.insert(str);
+		}
+	}
+}
+
 Building& BuildingDescr::create(EditorGameBase& egbase,
                                 Player& owner,
                                 Coords const pos,

=== modified file 'src/logic/map_objects/tribes/building.h'
--- src/logic/map_objects/tribes/building.h	2018-01-23 00:23:13 +0000
+++ src/logic/map_objects/tribes/building.h	2018-03-01 07:56:38 +0000
@@ -66,7 +66,7 @@
 	BuildingDescr(const std::string& init_descname,
 	              MapObjectType type,
 	              const LuaTable& t,
-	              const EditorGameBase& egbase);
+	              EditorGameBase* egbase);
 	~BuildingDescr() override {
 	}
 
@@ -80,6 +80,9 @@
 		return enhanced_building_;
 	}
 
+	/// Define a building that this building can be enhanced to. 'name' is the descr().name() of the other building.
+	void set_enhances_to(const std::string& name);
+
 	/**
 	 * The build cost for direct construction
 	 */

=== modified file 'src/logic/map_objects/tribes/carrier.cc'
--- src/logic/map_objects/tribes/carrier.cc	2017-08-19 22:22:20 +0000
+++ src/logic/map_objects/tribes/carrier.cc	2018-03-01 07:56:38 +0000
@@ -568,7 +568,7 @@
 
 CarrierDescr::CarrierDescr(const std::string& init_descname,
                            const LuaTable& table,
-                           const EditorGameBase& egbase)
+                           EditorGameBase* egbase)
    : WorkerDescr(init_descname, MapObjectType::CARRIER, table, egbase),
      ware_hotspot_(Vector2i(0, 15)) {
 	if (table.has_key("ware_hotspot")) {

=== modified file 'src/logic/map_objects/tribes/carrier.h'
--- src/logic/map_objects/tribes/carrier.h	2017-11-26 14:44:23 +0000
+++ src/logic/map_objects/tribes/carrier.h	2018-03-01 07:56:38 +0000
@@ -29,7 +29,7 @@
 public:
 	CarrierDescr(const std::string& init_descname,
 	             const LuaTable& table,
-	             const EditorGameBase& egbase);
+	             EditorGameBase* egbase);
 	~CarrierDescr() override {
 	}
 

=== modified file 'src/logic/map_objects/tribes/constructionsite.cc'
--- src/logic/map_objects/tribes/constructionsite.cc	2017-12-17 17:47:34 +0000
+++ src/logic/map_objects/tribes/constructionsite.cc	2018-03-01 07:56:38 +0000
@@ -77,7 +77,7 @@
   */
 ConstructionSiteDescr::ConstructionSiteDescr(const std::string& init_descname,
                                              const LuaTable& table,
-                                             const EditorGameBase& egbase)
+                                             EditorGameBase* egbase)
    : BuildingDescr(init_descname, MapObjectType::CONSTRUCTIONSITE, table, egbase) {
 	add_attribute(MapObject::CONSTRUCTIONSITE);
 }

=== modified file 'src/logic/map_objects/tribes/constructionsite.h'
--- src/logic/map_objects/tribes/constructionsite.h	2017-12-17 17:47:34 +0000
+++ src/logic/map_objects/tribes/constructionsite.h	2018-03-01 07:56:38 +0000
@@ -72,7 +72,7 @@
 public:
 	ConstructionSiteDescr(const std::string& init_descname,
 	                      const LuaTable& t,
-	                      const EditorGameBase& egbase);
+	                      EditorGameBase* egbase);
 	~ConstructionSiteDescr() override {
 	}
 

=== modified file 'src/logic/map_objects/tribes/dismantlesite.cc'
--- src/logic/map_objects/tribes/dismantlesite.cc	2017-12-17 17:47:34 +0000
+++ src/logic/map_objects/tribes/dismantlesite.cc	2018-03-01 07:56:38 +0000
@@ -45,7 +45,7 @@
 
 DismantleSiteDescr::DismantleSiteDescr(const std::string& init_descname,
                                        const LuaTable& table,
-                                       const EditorGameBase& egbase)
+                                       EditorGameBase* egbase)
    : BuildingDescr(init_descname, MapObjectType::DISMANTLESITE, table, egbase) {
 	add_attribute(MapObject::Attribute::CONSTRUCTIONSITE);  // Yep, this is correct.
 }

=== modified file 'src/logic/map_objects/tribes/dismantlesite.h'
--- src/logic/map_objects/tribes/dismantlesite.h	2017-08-18 17:32:16 +0000
+++ src/logic/map_objects/tribes/dismantlesite.h	2018-03-01 07:56:38 +0000
@@ -47,7 +47,7 @@
 public:
 	DismantleSiteDescr(const std::string& init_descname,
 	                   const LuaTable& t,
-	                   const EditorGameBase& egbase);
+	                   EditorGameBase* egbase);
 	~DismantleSiteDescr() override {
 	}
 

=== modified file 'src/logic/map_objects/tribes/market.cc'
--- src/logic/map_objects/tribes/market.cc	2017-10-04 00:27:47 +0000
+++ src/logic/map_objects/tribes/market.cc	2018-03-01 07:56:38 +0000
@@ -29,12 +29,12 @@
 
 MarketDescr::MarketDescr(const std::string& init_descname,
                          const LuaTable& table,
-                         const EditorGameBase& egbase)
+                         EditorGameBase* egbase)
    : BuildingDescr(init_descname, MapObjectType::MARKET, table, egbase) {
 	i18n::Textdomain td("tribes");
 
-	DescriptionIndex const woi = egbase.tribes().worker_index(table.get_string("carrier"));
-	if (!egbase.tribes().worker_exists(woi)) {
+	DescriptionIndex const woi = egbase->tribes().worker_index(table.get_string("carrier"));
+	if (!egbase->tribes().worker_exists(woi)) {
 		throw wexception("The tribe does not define the worker in 'carrier'.");
 	}
 	carrier_ = woi;

=== modified file 'src/logic/map_objects/tribes/market.h'
--- src/logic/map_objects/tribes/market.h	2017-10-04 00:27:47 +0000
+++ src/logic/map_objects/tribes/market.h	2018-03-01 07:56:38 +0000
@@ -30,7 +30,7 @@
 
 class MarketDescr : public BuildingDescr {
 public:
-	MarketDescr(const std::string& init_descname, const LuaTable& t, const EditorGameBase& egbase);
+	MarketDescr(const std::string& init_descname, const LuaTable& t, EditorGameBase* egbase);
 	~MarketDescr() override {
 	}
 

=== modified file 'src/logic/map_objects/tribes/militarysite.cc'
--- src/logic/map_objects/tribes/militarysite.cc	2017-11-30 10:59:06 +0000
+++ src/logic/map_objects/tribes/militarysite.cc	2018-03-01 07:56:38 +0000
@@ -295,7 +295,7 @@
   */
 MilitarySiteDescr::MilitarySiteDescr(const std::string& init_descname,
                                      const LuaTable& table,
-                                     const EditorGameBase& egbase)
+                                     EditorGameBase* egbase)
    : BuildingDescr(init_descname, MapObjectType::MILITARYSITE, table, egbase),
      conquer_radius_(0),
      num_soldiers_(0),

=== modified file 'src/logic/map_objects/tribes/militarysite.h'
--- src/logic/map_objects/tribes/militarysite.h	2017-11-26 14:44:23 +0000
+++ src/logic/map_objects/tribes/militarysite.h	2018-03-01 07:56:38 +0000
@@ -45,7 +45,7 @@
 public:
 	MilitarySiteDescr(const std::string& init_descname,
 	                  const LuaTable& t,
-	                  const EditorGameBase& egbase);
+	                  EditorGameBase* egbase);
 	~MilitarySiteDescr() override {
 	}
 

=== modified file 'src/logic/map_objects/tribes/production_program.cc'
--- src/logic/map_objects/tribes/production_program.cc	2017-12-02 11:41:19 +0000
+++ src/logic/map_objects/tribes/production_program.cc	2018-03-01 07:56:38 +0000
@@ -141,7 +141,7 @@
 						}
 					}
 					return new ProductionProgram::ActReturn::EconomyNeedsWare(wareindex);
-				} else if (tribes.worker_exists(tribes.worker_index(type_name))) {
+				} else if (tribes.worker_exists(type_name)) {
 					const DescriptionIndex& workerindex = tribes.worker_index(type_name);
 					for (int i = 0; i < static_cast<int>(tribes.nrtribes()); ++i) {
 						const TribeDescr* tribe_descr = tribes.get_tribe_descr(i);

=== modified file 'src/logic/map_objects/tribes/productionsite.cc'
--- src/logic/map_objects/tribes/productionsite.cc	2017-09-15 19:45:11 +0000
+++ src/logic/map_objects/tribes/productionsite.cc	2018-03-01 07:56:38 +0000
@@ -90,7 +90,7 @@
                                          const std::string& msgctxt,
                                          MapObjectType init_type,
                                          const LuaTable& table,
-                                         const EditorGameBase& egbase)
+                                         EditorGameBase* egbase)
    : BuildingDescr(init_descname, init_type, table, egbase),
      out_of_resource_productivity_threshold_(100) {
 	i18n::Textdomain td("tribes");
@@ -113,15 +113,15 @@
 	if (table.has_key("outputs")) {
 		for (const std::string& output : table.get_table("outputs")->array_entries<std::string>()) {
 			try {
-				DescriptionIndex idx = egbase.tribes().ware_index(output);
-				if (egbase.tribes().ware_exists(idx)) {
+				DescriptionIndex idx = egbase->tribes().ware_index(output);
+				if (egbase->tribes().ware_exists(idx)) {
 					if (output_ware_types_.count(idx)) {
 						throw wexception("this ware type has already been declared as an output");
 					}
 					output_ware_types_.insert(idx);
 				} else {
-					idx = egbase.tribes().worker_index(output);
-					if (egbase.tribes().worker_exists(idx)) {
+					idx = egbase->tribes().worker_index(output);
+					if (egbase->tribes().worker_exists(idx)) {
 						if (output_worker_types_.count(idx)) {
 							throw wexception("this worker type has already been declared as an output");
 						}
@@ -146,8 +146,8 @@
 				if (amount < 1 || 255 < amount) {
 					throw wexception("amount is out of range 1 .. 255");
 				}
-				DescriptionIndex idx = egbase.tribes().ware_index(ware_name);
-				if (egbase.tribes().ware_exists(idx)) {
+				DescriptionIndex idx = egbase->tribes().ware_index(ware_name);
+				if (egbase->tribes().ware_exists(idx)) {
 					for (const auto& temp_inputs : input_wares()) {
 						if (temp_inputs.first == idx) {
 							throw wexception("duplicated");
@@ -155,8 +155,8 @@
 					}
 					input_wares_.push_back(WareAmount(idx, amount));
 				} else {
-					idx = egbase.tribes().worker_index(ware_name);
-					if (egbase.tribes().worker_exists(idx)) {
+					idx = egbase->tribes().worker_index(ware_name);
+					if (egbase->tribes().worker_exists(idx)) {
 						for (const auto& temp_inputs : input_workers()) {
 							if (temp_inputs.first == idx) {
 								throw wexception("duplicated");
@@ -173,7 +173,7 @@
 		}
 	}
 
-	parse_working_positions(egbase, table.get_table("working_positions").get(), &working_positions_);
+	parse_working_positions(*egbase, table.get_table("working_positions").get(), &working_positions_);
 
 	// Get programs
 	items_table = table.get_table("programs");
@@ -193,7 +193,7 @@
 				program_descname = pgettext_expr(msgctxt.c_str(), program_descname_unlocalized.c_str());
 			}
 			programs_[program_name] = std::unique_ptr<ProductionProgram>(new ProductionProgram(
-			   program_name, program_descname, program_table->get_table("actions"), egbase, this));
+			   program_name, program_descname, program_table->get_table("actions"), *egbase, this));
 		} catch (const std::exception& e) {
 			throw wexception("program %s: %s", program_name.c_str(), e.what());
 		}
@@ -203,7 +203,7 @@
 ProductionSiteDescr::ProductionSiteDescr(const std::string& init_descname,
                                          const std::string& msgctxt,
                                          const LuaTable& table,
-                                         const EditorGameBase& egbase)
+                                         EditorGameBase* egbase)
    : ProductionSiteDescr(init_descname, msgctxt, MapObjectType::PRODUCTIONSITE, table, egbase) {
 }
 

=== modified file 'src/logic/map_objects/tribes/productionsite.h'
--- src/logic/map_objects/tribes/productionsite.h	2017-11-26 14:44:23 +0000
+++ src/logic/map_objects/tribes/productionsite.h	2018-03-01 07:56:38 +0000
@@ -63,11 +63,11 @@
 	                    const std::string& msgctxt,
 	                    MapObjectType type,
 	                    const LuaTable& t,
-	                    const EditorGameBase& egbase);
+	                    EditorGameBase* egbase);
 	ProductionSiteDescr(const std::string& init_descname,
 	                    const std::string& msgctxt,
 	                    const LuaTable& t,
-	                    const EditorGameBase& egbase);
+	                    EditorGameBase* egbase);
 
 	Building& create_object() const override;
 

=== modified file 'src/logic/map_objects/tribes/soldier.cc'
--- src/logic/map_objects/tribes/soldier.cc	2017-12-17 17:47:34 +0000
+++ src/logic/map_objects/tribes/soldier.cc	2018-03-01 07:56:38 +0000
@@ -63,7 +63,7 @@
 
 SoldierDescr::SoldierDescr(const std::string& init_descname,
                            const LuaTable& table,
-                           const EditorGameBase& egbase)
+                           EditorGameBase* egbase)
    : WorkerDescr(init_descname, MapObjectType::SOLDIER, table, egbase),
      health_(table.get_table("health")),
      attack_(table.get_table("attack")),

=== modified file 'src/logic/map_objects/tribes/soldier.h'
--- src/logic/map_objects/tribes/soldier.h	2017-06-24 08:47:46 +0000
+++ src/logic/map_objects/tribes/soldier.h	2018-03-01 07:56:38 +0000
@@ -41,7 +41,7 @@
 public:
 	friend class Economy;
 
-	SoldierDescr(const std::string& init_descname, const LuaTable& t, const EditorGameBase& egbase);
+	SoldierDescr(const std::string& init_descname, const LuaTable& t, EditorGameBase* egbase);
 	~SoldierDescr() override {
 	}
 

=== modified file 'src/logic/map_objects/tribes/trainingsite.cc'
--- src/logic/map_objects/tribes/trainingsite.cc	2017-11-09 17:37:13 +0000
+++ src/logic/map_objects/tribes/trainingsite.cc	2018-03-01 07:56:38 +0000
@@ -47,7 +47,7 @@
   */
 TrainingSiteDescr::TrainingSiteDescr(const std::string& init_descname,
                                      const LuaTable& table,
-                                     const EditorGameBase& egbase)
+                                     EditorGameBase* egbase)
    : ProductionSiteDescr(init_descname, "", MapObjectType::TRAININGSITE, table, egbase),
      num_soldiers_(table.get_int("soldier_capacity")),
      max_stall_(table.get_int("trainer_patience")),

=== modified file 'src/logic/map_objects/tribes/trainingsite.h'
--- src/logic/map_objects/tribes/trainingsite.h	2017-06-25 19:12:30 +0000
+++ src/logic/map_objects/tribes/trainingsite.h	2018-03-01 07:56:38 +0000
@@ -35,7 +35,7 @@
 public:
 	TrainingSiteDescr(const std::string& init_descname,
 	                  const LuaTable& table,
-	                  const EditorGameBase& egbase);
+	                  EditorGameBase* egbase);
 	~TrainingSiteDescr() override {
 	}
 

=== modified file 'src/logic/map_objects/tribes/tribe_descr.h'
--- src/logic/map_objects/tribes/tribe_descr.h	2018-01-10 16:21:50 +0000
+++ src/logic/map_objects/tribes/tribe_descr.h	2018-03-01 07:56:38 +0000
@@ -162,6 +162,8 @@
 	void add_building(const std::string& buildingname);
 
 private:
+	void calculate_trainingsites_proportions();
+
 	// Helper function for adding a special worker type (carriers etc.)
 	DescriptionIndex add_special_worker(const std::string& workername);
 	// Helper function for adding a special building type (port etc.)

=== modified file 'src/logic/map_objects/tribes/tribes.cc'
--- src/logic/map_objects/tribes/tribes.cc	2017-12-03 10:28:16 +0000
+++ src/logic/map_objects/tribes/tribes.cc	2018-03-01 07:56:38 +0000
@@ -34,31 +34,32 @@
      ships_(new DescriptionMaintainer<ShipDescr>()),
      wares_(new DescriptionMaintainer<WareDescr>()),
      workers_(new DescriptionMaintainer<WorkerDescr>()),
-     tribes_(new DescriptionMaintainer<TribeDescr>()) {
+     tribes_(new DescriptionMaintainer<TribeDescr>()),
+	  postload_data_(new PostloadData()) {
 }
 
-void Tribes::add_constructionsite_type(const LuaTable& table, const EditorGameBase& egbase) {
+void Tribes::add_constructionsite_type(const LuaTable& table, EditorGameBase* egbase) {
 	i18n::Textdomain td("tribes");
 	buildings_->add(new ConstructionSiteDescr(
 	   pgettext_expr(table.get_string("msgctxt").c_str(), table.get_string("descname").c_str()),
 	   table, egbase));
 }
 
-void Tribes::add_dismantlesite_type(const LuaTable& table, const EditorGameBase& egbase) {
+void Tribes::add_dismantlesite_type(const LuaTable& table, EditorGameBase* egbase) {
 	i18n::Textdomain td("tribes");
 	buildings_->add(new DismantleSiteDescr(
 	   pgettext_expr(table.get_string("msgctxt").c_str(), table.get_string("descname").c_str()),
 	   table, egbase));
 }
 
-void Tribes::add_militarysite_type(const LuaTable& table, const EditorGameBase& egbase) {
+void Tribes::add_militarysite_type(const LuaTable& table, EditorGameBase* egbase) {
 	i18n::Textdomain td("tribes");
 	buildings_->add(new MilitarySiteDescr(
 	   pgettext_expr(table.get_string("msgctxt").c_str(), table.get_string("descname").c_str()),
 	   table, egbase));
 }
 
-void Tribes::add_productionsite_type(const LuaTable& table, const EditorGameBase& egbase) {
+void Tribes::add_productionsite_type(const LuaTable& table, EditorGameBase* egbase) {
 	i18n::Textdomain td("tribes");
 	const std::string msgctxt = table.get_string("msgctxt");
 	buildings_->add(
@@ -66,21 +67,21 @@
 	                           msgctxt, table, egbase));
 }
 
-void Tribes::add_trainingsite_type(const LuaTable& table, const EditorGameBase& egbase) {
+void Tribes::add_trainingsite_type(const LuaTable& table, EditorGameBase* egbase) {
 	i18n::Textdomain td("tribes");
 	buildings_->add(new TrainingSiteDescr(
 	   pgettext_expr(table.get_string("msgctxt").c_str(), table.get_string("descname").c_str()),
 	   table, egbase));
 }
 
-void Tribes::add_warehouse_type(const LuaTable& table, const EditorGameBase& egbase) {
+void Tribes::add_warehouse_type(const LuaTable& table, EditorGameBase* egbase) {
 	i18n::Textdomain td("tribes");
 	buildings_->add(new WarehouseDescr(
 	   pgettext_expr(table.get_string("msgctxt").c_str(), table.get_string("descname").c_str()),
 	   table, egbase));
 }
 
-void Tribes::add_market_type(const LuaTable& table, const EditorGameBase& egbase) {
+void Tribes::add_market_type(const LuaTable& table, EditorGameBase* egbase) {
 	i18n::Textdomain td("tribes");
 	buildings_->add(new MarketDescr(
 	   pgettext_expr(table.get_string("msgctxt").c_str(), table.get_string("descname").c_str()),
@@ -106,21 +107,21 @@
 	   table));
 }
 
-void Tribes::add_carrier_type(const LuaTable& table, const EditorGameBase& egbase) {
+void Tribes::add_carrier_type(const LuaTable& table, EditorGameBase* egbase) {
 	i18n::Textdomain td("tribes");
 	workers_->add(new CarrierDescr(
 	   pgettext_expr(table.get_string("msgctxt").c_str(), table.get_string("descname").c_str()),
 	   table, egbase));
 }
 
-void Tribes::add_soldier_type(const LuaTable& table, const EditorGameBase& egbase) {
+void Tribes::add_soldier_type(const LuaTable& table, EditorGameBase* egbase) {
 	i18n::Textdomain td("tribes");
 	workers_->add(new SoldierDescr(
 	   pgettext_expr(table.get_string("msgctxt").c_str(), table.get_string("descname").c_str()),
 	   table, egbase));
 }
 
-void Tribes::add_worker_type(const LuaTable& table, const EditorGameBase& egbase) {
+void Tribes::add_worker_type(const LuaTable& table, EditorGameBase* egbase) {
 	i18n::Textdomain td("tribes");
 	workers_->add(new WorkerDescr(
 	   pgettext_expr(table.get_string("msgctxt").c_str(), table.get_string("descname").c_str()),
@@ -312,42 +313,96 @@
 	}
 }
 
+void Tribes::add_worker_buildcost(const WorkerBuildcost& buildcost) {
+	postload_data_->workers_buildcost_.push_back(buildcost);
+}
+
+void Tribes::add_mapobject_enhancement(const MapObjectEnhancement& becomes) {
+	postload_data_->mapobject_enhancements_.push_back(becomes);
+}
+
 void Tribes::postload() {
-	for (DescriptionIndex i = 0; i < buildings_->size(); ++i) {
-		BuildingDescr& building_descr = *buildings_->get_mutable(i);
-
-		// Add consumers and producers to wares.
-		if (upcast(ProductionSiteDescr, de, &building_descr)) {
-			for (const auto& ware_amount : de->input_wares()) {
-				wares_->get_mutable(ware_amount.first)->add_consumer(i);
-			}
-			for (const DescriptionIndex& wareindex : de->output_ware_types()) {
-				wares_->get_mutable(wareindex)->add_producer(i);
-			}
-			for (const auto& job : de->working_positions()) {
-				workers_->get_mutable(job.first)->add_employer(i);
-			}
-		}
-
-		// Register which buildings buildings can have been enhanced from
-		const DescriptionIndex& enhancement = building_descr.enhancement();
-		if (building_exists(enhancement)) {
-			buildings_->get_mutable(enhancement)->set_enhanced_from(i);
-		}
-	}
-
-	// Calculate the trainingsites proportions.
-	postload_calculate_trainingsites_proportions();
-
-	// Resize the configuration of our wares if they won't fit in the current window (12 = info label
-	// size).
-	int number = (g_gr->get_yres() - 290) / (WARE_MENU_PIC_HEIGHT + WARE_MENU_PIC_PAD_Y + 12);
-	for (DescriptionIndex i = 0; i < tribes_->size(); ++i) {
-		TribeDescr* tribe_descr = tribes_->get_mutable(i);
-		tribe_descr->resize_ware_orders(number);
-	}
+	try {
+		// Some workers have other workers as build cost, so we postload those in order to perform the necessary checks.
+		for (const WorkerBuildcost& buildcost : postload_data_->workers_buildcost_) {
+			if (!worker_exists(buildcost.worker)) {
+				throw GameDataError(
+					"Trying to add a worker buildcost to non-existing worker '%s'", buildcost.worker.c_str());
+			}
+			workers_->get_mutable(safe_worker_index(buildcost.worker))->add_wareworker_to_buildcost(buildcost.needed_worker, buildcost.quantity);
+		}
+
+		// Likewise, more experienced workers and advanced buildings might not have been available yet when a lower-level worker or building was loaded.
+		for (const MapObjectEnhancement& enhancement : postload_data_->mapobject_enhancements_) {
+			switch (enhancement.type) {
+			case MapObjectType::BUILDING:
+				if (!building_exists(enhancement.name)) {
+					throw GameDataError(
+						"Trying to add a building enhancement to non-existing building '%s'", enhancement.name.c_str());
+				}
+				if (!building_exists(enhancement.enhanced_name)) {
+					throw GameDataError(
+						"The building '%s' to be added as enhancement to the building '%s' does not exist", enhancement.enhanced_name.c_str(), enhancement.name.c_str());
+				}
+				buildings_->get_mutable(safe_building_index(enhancement.name))->set_enhances_to(enhancement.enhanced_name);
+				break;
+			case MapObjectType::WORKER:
+				if (!worker_exists(enhancement.name)) {
+					throw GameDataError(
+						"Trying to add a worker enhancement to non-existing worker '%s'", enhancement.name.c_str());
+				}
+				if (!worker_exists(enhancement.enhanced_name)) {
+					throw GameDataError(
+						"The worker '%s' to be added as enhancement to the worker '%s' does not exist", enhancement.enhanced_name.c_str(), enhancement.name.c_str());
+				}
+				workers_->get_mutable(safe_worker_index(enhancement.name))->set_becomes(enhancement.enhanced_name);
+				break;
+			default:
+				NEVER_HERE();
+			}
+		}
+
+		// Add building info to wares here, since wares were loaded first.
+		for (DescriptionIndex i = 0; i < buildings_->size(); ++i) {
+			BuildingDescr& building_descr = *buildings_->get_mutable(i);
+
+			// Add consumers and producers to wares.
+			if (upcast(ProductionSiteDescr, de, &building_descr)) {
+				for (const auto& ware_amount : de->input_wares()) {
+					wares_->get_mutable(ware_amount.first)->add_consumer(i);
+				}
+				for (const DescriptionIndex& wareindex : de->output_ware_types()) {
+					wares_->get_mutable(wareindex)->add_producer(i);
+				}
+				for (const auto& job : de->working_positions()) {
+					workers_->get_mutable(job.first)->add_employer(i);
+				}
+			}
+
+			// Register which buildings buildings can have been enhanced from
+			const DescriptionIndex& enhancement = building_descr.enhancement();
+			if (building_exists(enhancement)) {
+				buildings_->get_mutable(enhancement)->set_enhanced_from(i);
+			}
+		}
+
+		// Calculate the trainingsites proportions.
+		postload_calculate_trainingsites_proportions();
+
+		// Resize the configuration of our wares if they won't fit in the current window (12 = info label
+		// size)
+		int number = (g_gr->get_yres() - 290) / (WARE_MENU_PIC_HEIGHT + WARE_MENU_PIC_PAD_Y + 12);
+		for (DescriptionIndex i = 0; i < tribes_->size(); ++i) {
+			tribes_->get_mutable(i)->resize_ware_orders(number);
+		}
+	} catch (const WException& e) {
+		throw GameDataError("Error during tribes postload: %s", e.what());
+	}
+
+	postload_data_.reset(new PostloadData());
 }
 
+
 // Set default trainingsites proportions for AI. Make sure that we get a sum of ca. 100
 void Tribes::postload_calculate_trainingsites_proportions() {
 	for (DescriptionIndex i = 0; i < tribes_->size(); ++i) {

=== modified file 'src/logic/map_objects/tribes/tribes.h'
--- src/logic/map_objects/tribes/tribes.h	2017-12-02 12:43:38 +0000
+++ src/logic/map_objects/tribes/tribes.h	2018-03-01 07:56:38 +0000
@@ -53,25 +53,25 @@
 	}
 
 	/// Adds this building type to the tribe description.
-	void add_constructionsite_type(const LuaTable& table, const EditorGameBase& egbase);
-
-	/// Adds this building type to the tribe description.
-	void add_dismantlesite_type(const LuaTable& table, const EditorGameBase& egbase);
-
-	/// Adds this building type to the tribe description.
-	void add_militarysite_type(const LuaTable& table, const EditorGameBase& egbase);
-
-	/// Adds this building type to the tribe description.
-	void add_productionsite_type(const LuaTable& table, const EditorGameBase& egbase);
-
-	/// Adds this building type to the tribe description.
-	void add_trainingsite_type(const LuaTable& table, const EditorGameBase& egbase);
-
-	/// Adds this building type to the tribe description.
-	void add_warehouse_type(const LuaTable& table, const EditorGameBase& egbase);
-
-	/// Adds this building type to the tribe description.
-	void add_market_type(const LuaTable& table, const EditorGameBase& egbase);
+	void add_constructionsite_type(const LuaTable& table, EditorGameBase* egbase);
+
+	/// Adds this building type to the tribe description.
+	void add_dismantlesite_type(const LuaTable& table, EditorGameBase* egbase);
+
+	/// Adds this building type to the tribe description.
+	void add_militarysite_type(const LuaTable& table, EditorGameBase* egbase);
+
+	/// Adds this building type to the tribe description.
+	void add_productionsite_type(const LuaTable& table, EditorGameBase* egbase);
+
+	/// Adds this building type to the tribe description.
+	void add_trainingsite_type(const LuaTable& table, EditorGameBase* egbase);
+
+	/// Adds this building type to the tribe description.
+	void add_warehouse_type(const LuaTable& table, EditorGameBase* egbase);
+
+	/// Adds this building type to the tribe description.
+	void add_market_type(const LuaTable& table, EditorGameBase* egbase);
 
 	/// Adds this immovable type to the tribe description.
 	void add_immovable_type(const LuaTable& table);
@@ -83,13 +83,13 @@
 	void add_ware_type(const LuaTable& table);
 
 	/// Adds this worker type to the tribe description.
-	void add_carrier_type(const LuaTable& table, const EditorGameBase& egbase);
-
-	/// Adds this worker type to the tribe description.
-	void add_soldier_type(const LuaTable& table, const EditorGameBase& egbase);
-
-	/// Adds this worker type to the tribe description.
-	void add_worker_type(const LuaTable& table, const EditorGameBase& egbase);
+	void add_carrier_type(const LuaTable& table, EditorGameBase* egbase);
+
+	/// Adds this worker type to the tribe description.
+	void add_soldier_type(const LuaTable& table, EditorGameBase* egbase);
+
+	/// Adds this worker type to the tribe description.
+	void add_worker_type(const LuaTable& table, EditorGameBase* egbase);
 
 	/// Adds a specific tribe's configuration.
 	void add_tribe(const LuaTable& table, const EditorGameBase& egbase);
@@ -143,6 +143,22 @@
 	/// Complete the Description objects' information with data from other Description objects.
 	void postload();
 
+	/// Some workers have other workers as part of their buildcost. If the other worker hasn't been loaded yet, it will need to be added during postload.
+	struct WorkerBuildcost {
+		const std::string worker;
+		const std::string needed_worker;
+		const Quantity quantity;
+	};
+	void add_worker_buildcost(const WorkerBuildcost& buildcost);
+
+	/// Enhanced buildings/workers might not have been loaded yet when a more basic type is being loaded, so we will need to add some of them during postload.
+	struct MapObjectEnhancement {
+		const MapObjectType type; // Worker or building
+		const std::string name;
+		const std::string enhanced_name;
+	};
+	void add_mapobject_enhancement(const MapObjectEnhancement& becomes);
+
 private:
 	void postload_calculate_trainingsites_proportions();
 
@@ -153,6 +169,17 @@
 	std::unique_ptr<DescriptionMaintainer<WorkerDescr>> workers_;
 	std::unique_ptr<DescriptionMaintainer<TribeDescr>> tribes_;
 
+	struct PostloadData {
+		/// Worker buildcost records to be added in postload.
+		std::vector<WorkerBuildcost> workers_buildcost_;
+		/// Worker/Building enhancement records to be added in postload.
+		std::vector<MapObjectEnhancement> mapobject_enhancements_;
+
+	};
+
+	/// Records to be added in postload. This will be empty after postload.
+	std::unique_ptr<PostloadData> postload_data_;
+
 	DISALLOW_COPY_AND_ASSIGN(Tribes);
 };
 

=== modified file 'src/logic/map_objects/tribes/warehouse.cc'
--- src/logic/map_objects/tribes/warehouse.cc	2017-08-30 12:06:20 +0000
+++ src/logic/map_objects/tribes/warehouse.cc	2018-03-01 07:56:38 +0000
@@ -292,7 +292,7 @@
   */
 WarehouseDescr::WarehouseDescr(const std::string& init_descname,
                                const LuaTable& table,
-                               const EditorGameBase& egbase)
+                               EditorGameBase* egbase)
    : BuildingDescr(init_descname, MapObjectType::WAREHOUSE, table, egbase),
      conquers_(0),
      heal_per_second_(0) {

=== modified file 'src/logic/map_objects/tribes/warehouse.h'
--- src/logic/map_objects/tribes/warehouse.h	2017-11-26 14:44:23 +0000
+++ src/logic/map_objects/tribes/warehouse.h	2018-03-01 07:56:38 +0000
@@ -50,7 +50,7 @@
 public:
 	WarehouseDescr(const std::string& init_descname,
 	               const LuaTable& t,
-	               const EditorGameBase& egbase);
+	               EditorGameBase* egbase);
 	~WarehouseDescr() override {
 	}
 

=== modified file 'src/logic/map_objects/tribes/worker_descr.cc'
--- src/logic/map_objects/tribes/worker_descr.cc	2017-11-12 16:30:35 +0000
+++ src/logic/map_objects/tribes/worker_descr.cc	2018-03-01 07:56:38 +0000
@@ -38,12 +38,12 @@
 WorkerDescr::WorkerDescr(const std::string& init_descname,
                          MapObjectType init_type,
                          const LuaTable& table,
-                         const EditorGameBase& egbase)
+                         EditorGameBase* egbase)
    : BobDescr(init_descname, init_type, MapObjectDescr::OwnerType::kTribe, table),
      buildable_(false),
      needed_experience_(INVALID_INDEX),
      becomes_(INVALID_INDEX),
-     egbase_(egbase) {
+     egbase_(*egbase) {
 	if (helptext_script().empty()) {
 		throw GameDataError("Worker %s has no helptext script", name().c_str());
 	}
@@ -59,21 +59,17 @@
 		items_table = table.get_table("buildcost");
 		for (const std::string& key : items_table->keys<std::string>()) {
 			try {
-				if (buildcost_.count(key)) {
-					throw GameDataError(
-					   "a buildcost item of this ware type has already been defined: %s", key.c_str());
-				}
-				if (!tribes.ware_exists(tribes.ware_index(key)) &&
-				    !tribes.worker_exists(tribes.worker_index(key))) {
-					throw GameDataError("\"%s\" has not been defined as a ware/worker type (wrong "
-					                    "declaration order?)",
-					                    key.c_str());
-				}
-				int32_t value = items_table->get_int(key);
-				uint8_t const count = value;
-				if (count != value)
+				int32_t temp_quantity = items_table->get_int(key);
+				const uint8_t quantity = temp_quantity;
+				if (quantity != temp_quantity) {
 					throw GameDataError("count is out of range 1 .. 255");
-				buildcost_.insert(std::pair<std::string, uint8_t>(key, count));
+				}
+				if (tribes.ware_exists(key)) {
+					add_wareworker_to_buildcost(key, quantity);
+				} else {
+					// The buildcost's worker might not have been loaded yet, so we'll try this again in postload.
+					egbase->mutable_tribes()->add_worker_buildcost({name(), key, quantity});
+				}
 			} catch (const WException& e) {
 				throw GameDataError("[buildcost] \"%s\": %s", key.c_str(), e.what());
 			}
@@ -92,8 +88,9 @@
 
 	// Read what the worker can become and the needed experience
 	if (table.has_key("becomes")) {
-		becomes_ = egbase_.tribes().safe_worker_index(table.get_string("becomes"));
 		needed_experience_ = table.get_int("experience");
+		// The expert worker might not have been loaded yet, so we'll do this in postload.
+		egbase->mutable_tribes()->add_mapobject_enhancement({MapObjectType::WORKER, name(), table.get_string("becomes")});
 	}
 
 	// Read programs
@@ -123,13 +120,30 @@
 
 WorkerDescr::WorkerDescr(const std::string& init_descname,
                          const LuaTable& table,
-                         const EditorGameBase& egbase)
+                         EditorGameBase* egbase)
    : WorkerDescr(init_descname, MapObjectType::WORKER, table, egbase) {
 }
 
 WorkerDescr::~WorkerDescr() {
 }
 
+void WorkerDescr::add_wareworker_to_buildcost(const std::string& ww_name, uint8_t quantity) {
+	if (buildcost_.count(ww_name) != 0) {
+		throw GameDataError("\"%s\" already exists as build cost for %s", ww_name.c_str(), name().c_str());
+	}
+	if (!egbase_.tribes().ware_exists(ww_name) && !egbase_.tribes().worker_exists(ww_name)) {
+						throw GameDataError("\"%s\" has not been defined as a ware/worker type (wrong "
+												  "declaration order?) while loading %s",
+												  ww_name.c_str(), name().c_str());
+	}
+	buildcost_.insert(std::make_pair(ww_name, quantity));
+}
+
+void WorkerDescr::set_becomes(const std::string& becomes_name) {
+	assert(needed_experience_ > 0 && needed_experience_ != INVALID_INDEX);
+	becomes_ = egbase_.tribes().safe_worker_index(becomes_name);
+}
+
 /**
  * Get a program from the workers description.
  */

=== modified file 'src/logic/map_objects/tribes/worker_descr.h'
--- src/logic/map_objects/tribes/worker_descr.h	2017-11-12 14:54:46 +0000
+++ src/logic/map_objects/tribes/worker_descr.h	2018-03-01 07:56:38 +0000
@@ -43,13 +43,13 @@
 	friend struct WorkerProgram;
 
 public:
-	using Buildcost = std::map<std::string, Quantity>;
+	using Buildcost = std::map<std::string, uint8_t>;
 
 	WorkerDescr(const std::string& init_descname,
 	            MapObjectType type,
 	            const LuaTable& table,
-	            const EditorGameBase& egbase);
-	WorkerDescr(const std::string& init_descname, const LuaTable& t, const EditorGameBase& egbase);
+	            EditorGameBase* egbase);
+	WorkerDescr(const std::string& init_descname, const LuaTable& t, EditorGameBase* egbase);
 	~WorkerDescr() override;
 
 	Bob& create_object() const override;
@@ -62,6 +62,14 @@
 		return buildcost_;
 	}
 
+	/// Some workers need to be added to the buildcost in postload, because the other worker might not have been loaded into the engine yet.
+	/// 'name' is the descr().name() of the other worker, 'quantity' is the amount of that woker type needed.
+	void add_wareworker_to_buildcost(const std::string& name, uint8_t quantity);
+
+	/// Sets the descr().name() of the worker that this worker will enhance to, given enough experience.
+	/// 'needed_experience_' needs to be set first.
+	void set_becomes(const std::string& name);
+
 	/// How much of the worker type that an economy should store in warehouses.
 	/// The special value std::numeric_limits<uint32_t>::max() means that the
 	/// the target quantity of this ware type will never be checked and should

=== modified file 'src/scripting/lua_root.cc'
--- src/scripting/lua_root.cc	2017-11-25 18:29:22 +0000
+++ src/scripting/lua_root.cc	2018-03-01 07:56:38 +0000
@@ -564,8 +564,8 @@
 
 	try {
 		LuaTable table(L);  // Will pop the table eventually.
-		EditorGameBase& egbase = get_egbase(L);
-		egbase.mutable_tribes()->add_constructionsite_type(table, egbase);
+		EditorGameBase* egbase = &get_egbase(L);
+		egbase->mutable_tribes()->add_constructionsite_type(table, egbase);
 	} catch (std::exception& e) {
 		report_error(L, "%s", e.what());
 	}
@@ -588,8 +588,8 @@
 
 	try {
 		LuaTable table(L);  // Will pop the table eventually.
-		EditorGameBase& egbase = get_egbase(L);
-		egbase.mutable_tribes()->add_dismantlesite_type(table, egbase);
+		EditorGameBase* egbase = &get_egbase(L);
+		egbase->mutable_tribes()->add_dismantlesite_type(table, egbase);
 	} catch (std::exception& e) {
 		report_error(L, "%s", e.what());
 	}
@@ -612,8 +612,8 @@
 
 	try {
 		LuaTable table(L);  // Will pop the table eventually.
-		EditorGameBase& egbase = get_egbase(L);
-		egbase.mutable_tribes()->add_militarysite_type(table, egbase);
+		EditorGameBase* egbase = &get_egbase(L);
+		egbase->mutable_tribes()->add_militarysite_type(table, egbase);
 	} catch (std::exception& e) {
 		report_error(L, "%s", e.what());
 	}
@@ -636,8 +636,8 @@
 
 	try {
 		LuaTable table(L);  // Will pop the table eventually.
-		EditorGameBase& egbase = get_egbase(L);
-		egbase.mutable_tribes()->add_productionsite_type(table, egbase);
+		EditorGameBase* egbase = &get_egbase(L);
+		egbase->mutable_tribes()->add_productionsite_type(table, egbase);
 	} catch (std::exception& e) {
 		report_error(L, "%s", e.what());
 	}
@@ -660,8 +660,8 @@
 
 	try {
 		LuaTable table(L);  // Will pop the table eventually.
-		EditorGameBase& egbase = get_egbase(L);
-		egbase.mutable_tribes()->add_trainingsite_type(table, egbase);
+		EditorGameBase* egbase = &get_egbase(L);
+		egbase->mutable_tribes()->add_trainingsite_type(table, egbase);
 	} catch (std::exception& e) {
 		report_error(L, "%s", e.what());
 	}
@@ -684,8 +684,8 @@
 
 	try {
 		LuaTable table(L);  // Will pop the table eventually.
-		EditorGameBase& egbase = get_egbase(L);
-		egbase.mutable_tribes()->add_warehouse_type(table, egbase);
+		EditorGameBase* egbase = &get_egbase(L);
+		egbase->mutable_tribes()->add_warehouse_type(table, egbase);
 	} catch (std::exception& e) {
 		report_error(L, "%s", e.what());
 	}
@@ -708,8 +708,8 @@
 
 	try {
 		LuaTable table(L);  // Will pop the table eventually.
-		EditorGameBase& egbase = get_egbase(L);
-		egbase.mutable_tribes()->add_market_type(table, egbase);
+		EditorGameBase* egbase = &get_egbase(L);
+		egbase->mutable_tribes()->add_market_type(table, egbase);
 	} catch (std::exception& e) {
 		report_error(L, "%s", e.what());
 	}
@@ -800,8 +800,8 @@
 
 	try {
 		LuaTable table(L);  // Will pop the table eventually.
-		EditorGameBase& egbase = get_egbase(L);
-		egbase.mutable_tribes()->add_carrier_type(table, egbase);
+		EditorGameBase* egbase = &get_egbase(L);
+		egbase->mutable_tribes()->add_carrier_type(table, egbase);
 	} catch (std::exception& e) {
 		report_error(L, "%s", e.what());
 	}
@@ -823,8 +823,8 @@
 
 	try {
 		LuaTable table(L);  // Will pop the table eventually.
-		EditorGameBase& egbase = get_egbase(L);
-		egbase.mutable_tribes()->add_soldier_type(table, egbase);
+		EditorGameBase* egbase = &get_egbase(L);
+		egbase->mutable_tribes()->add_soldier_type(table, egbase);
 	} catch (std::exception& e) {
 		report_error(L, "%s", e.what());
 	}
@@ -846,8 +846,8 @@
 
 	try {
 		LuaTable table(L);  // Will pop the table eventually.
-		EditorGameBase& egbase = get_egbase(L);
-		egbase.mutable_tribes()->add_worker_type(table, egbase);
+		EditorGameBase* egbase = &get_egbase(L);
+		egbase->mutable_tribes()->add_worker_type(table, egbase);
 	} catch (std::exception& e) {
 		report_error(L, "%s", e.what());
 	}