Merge ~amzn-cmiller/cloud-init:read-version_errors into cloud-init:master

[Chad]

tools/read-version: handle errors

When the cloned branch was not the canonical upstream and tags were not
available, tox would fail because tools/read-version would fail, and
tragically never print the advice that is in tools/read-version about
how to fix it.

This changes tools/read-version to catch the exception that is elsewhere
explicitly thrown and treat that too as an error it can handle.

[Ryan Harper (raharper)]

Chad,

what's the next steps here? I see you've targeted this to someone elses branch. Is there still work or should this be dropped/closed?

[Ryan Harper (raharper)]

I'm sorry, my mistake Chad. This _is_ your branch, I had a different Chad in my mind.

[Server Team CI bot (server-team-bot)]

PASSED: Continuous integration, rev:39185f5f7e29d3239ece644bade9a070efc41920
https://jenkins.ubuntu.com/server/job/cloud-init-ci/671/
Executed test runs:
    SUCCESS: Checkout
    SUCCESS: Unit & Style Tests
    SUCCESS: Ubuntu LTS: Build
    SUCCESS: Ubuntu LTS: Integration
    IN_PROGRESS: Declarative: Post Actions

Click here to trigger a rebuild:
https://jenkins.ubuntu.com/server/job/cloud-init-ci/671/rebuild

review: Approve (continuous-integration)

[Server Team CI bot (server-team-bot)]

review: Approve (continuous-integration)

[Server Team CI bot (server-team-bot)]

Commit message lints:
 - Line #0 has 151 too many characters. Line starts with: "When the cloned branch"... - Line #2 has 62 too many characters. Line starts with: "This changes tools/read-version"...

review: Needs Fixing

[Server Team CI bot (server-team-bot)]

review: Approve (continuous-integration)

[Server Team CI bot (server-team-bot)]

Commit message lints:
 - Line #2 has 151 too many characters. Line starts with: "When the cloned branch"... - Line #4 has 62 too many characters. Line starts with: "This changes tools/read-version"...

review: Needs Fixing

[Server Team CI bot (server-team-bot)]

review: Approve (continuous-integration)

diff --git a/tools/read-version b/tools/read-version
index e69c2ce..6dca659 100755
--- a/tools/read-version
+++ b/tools/read-version
@@ -71,9 +71,12 @@ if is_gitdir(_tdir) and which("git"):
         flags = ['--tags']
     cmd = ['git', 'describe', '--abbrev=8', '--match=[0-9]*'] + flags
 
-    version = tiny_p(cmd).strip()
+    try:
+        version = tiny_p(cmd).strip()
+    except RuntimeError:
+        version = None
 
-    if not version.startswith(src_version):
+    if version is None or not version.startswith(src_version):
         sys.stderr.write("git describe version (%s) differs from "
                          "cloudinit.version (%s)\n" % (version, src_version))
         sys.stderr.write(