Merge lp:~vorlon/ubuntu/natty/eglibc/multiarch-support into lp:ubuntu/natty/eglibc

[Steve Langasek]

Currently, trying to install any foreign arch libraries with apt will fail with this error:

  E: Couldn't configure pre-depend multiarch-support for libgcc1, probably a dependency cycle.

This is correct behavior on the part of apt. libc6 Provides: multiarch-support, libgcc1 Pre-Depends: multiarch-support, libc6 Depends: libgcc1.

The proposed branch will break this dependency loop for foreign arch packages by making 'multiarch-support' a real, Multi-Arch: foreign package depending on the native libc to satisfy these dependencies. I believe this should have no effect on the native system, which avoids this dependency loop by having the necessary libraries installed before apt is ever called; and I believe it's safe for foreign architectures because a) there's no way you're getting a foreign libc unpacked, *period*, unless it's already Multi-Arch: same, and there should be no libc package that's Multi-Arch: same that doesn't also support the multiarch paths; and b) it's the foreign arch, so if I'm wrong about this there's no danger to the package manager's integrity (you can't cross-grade the base system yet).

But it's late in the cycle and this is a new (if contentless) binary package being added to the base system, so I'm requesting the release team's review before landing this change.

[Steve Langasek (vorlon)]

Hmm, just noticed that requesting review from 'ubuntu-release' didn't seem to actually generate any useful mails. Requesting review from Colin and/or Martin explicitly.

[Steve Langasek (vorlon)]

BTW, have upgrade-tested this in ppa and maverick->natty and natty->natty both go fine.

[Martin Pitt (pitti)]

The reasoning makes sense to me. However, what I don't understand why the new "multiarch-support" real package is described as being transitional? As far as I understood, the reason for existing won't go away after an upgrade?

[Steve Langasek (vorlon)]

It's transitional because after a full release cycle or so, there will be no libc6 that doesn't provide this support, so we can drop the pre-depends.

[Martin Pitt (pitti)]

Ah, thanks for the clarification. Seems fine to me then.

[Martin Pitt (pitti)]

review: Approve

[Colin Watson (cjwatson)]

Makes sense to me too, for the record.

review: Approve

=== modified file 'debian/changelog'
--- debian/changelog	2011-03-19 21:22:50 +0000
+++ debian/changelog	2011-03-20 21:42:49 +0000
@@ -5,6 +5,16 @@
   * debian/sysdeps/armhf.mk: use /lib/$(DEB_HOST_MULTIARCH) for rtlddir, so
     that we avoid a file conflict with the armel libc and armel+armhf can
     be multiarch-coinstallable.
+  * debian/control.in/libc, debian/control.in/main: make multiarch-support a
+    real package depending on the native libc; this eliminates the problem
+    of a circular depends/pre-depends loop never permitting apt to install
+    the base libraries for any foreign architecture.  We still have the
+    dependency loop for the native architecture, which is safe (and needs to
+    be enforced!), but whenever a package is installed non-native, it's ok
+    to bypass this requirement (which is effectively what we're doing by
+    making multiarch-support Multi-Arch: foreign), because none of the
+    concerned library packages are installable at all unless a Multi-Arch:
+    same libc6 is available.
 
  -- Steve Langasek <[e-mail]>  Thu, 17 Mar 2011 22:49:13 -0700
 
 
=== modified file 'debian/control'
--- debian/control	2011-03-15 16:44:57 +0000
+++ debian/control	2011-03-20 21:42:49 +0000
@@ -117,6 +117,20 @@
  query. You should install this package only if you use
  slow Services like LDAP, NIS or NIS+
 
+Package: multiarch-support
+Architecture: any
+Multi-Arch: foreign
+Depends: libc6 (>= 2.3.6-2) [!any-i386 !alpha !ia64 !hurd-any !kfreebsd-any],
+         libc6.1 (>= 2.3.6-2) [alpha ia64],
+         libc0.3 (>= 2.3.6-2) [hurd-any],
+         libc0.1 (>= 2.3.6-2) [kfreebsd-any],
+         libc6 (>= 2.13-0ubuntu6) [any-i386]
+Priority: standard
+Description: Transitional package to ensure multiarch compatibility
+ This is a transitional package used to ensure multiarch support is present
+ in ld.so before unpacking libraries to the multiarch directories.  It can
+ be removed once nothing on the system depends on it.
+
 Package: libc6
 Architecture: amd64 arm armeb armel armhf i386 lpia m32r m68k mips mipsel powerpc powerpcspe ppc64 sparc sparc64 s390 hppa sh3 sh4 sh3eb sh4eb
 Section: libs
@@ -125,7 +139,7 @@
 Depends: libc-bin (= ${binary:Version}), hurd (>= 20070606-1+SVN) [hurd-i386], libgcc1 [!hppa !m68k], libgcc2 [m68k], libgcc4 [hppa], tzdata
 Recommends: libc0.1-i686 [kfreebsd-i386], libc0.3-i686 [hurd-i386]
 Suggests: glibc-doc, debconf | debconf-2.0, locales [!hurd-i386]
-Provides: ${locale-compat:Depends}, libc6-i686 [i386], libc6-sparcv9b [sparc sparc64], multiarch-support
+Provides: ${locale-compat:Depends}, libc6-i686 [i386], libc6-sparcv9b [sparc sparc64]
 Conflicts: tzdata-etch, tzdata (<< 2007k-1), prelink (<< 0.0.20090925), belocs-locales-bin, libc6-i686 [i386]
 Replaces: belocs-locales-bin,
 	libc6-amd64 [amd64],
@@ -211,7 +225,7 @@
 Depends: libc-bin (= ${binary:Version}), hurd (>= 20070606-1+SVN) [hurd-i386], libgcc1 [!hppa !m68k], libgcc2 [m68k], libgcc4 [hppa], tzdata
 Recommends: libc0.1-i686 [kfreebsd-i386], libc0.3-i686 [hurd-i386]
 Suggests: glibc-doc, debconf | debconf-2.0, locales [!hurd-i386]
-Provides: ${locale-compat:Depends}, libc6-i686 [i386], libc6-sparcv9b [sparc sparc64], multiarch-support
+Provides: ${locale-compat:Depends}, libc6-i686 [i386], libc6-sparcv9b [sparc sparc64]
 Conflicts: tzdata-etch, tzdata (<< 2007k-1), prelink (<< 0.0.20090925), belocs-locales-bin, libc6-i686 [i386]
 Replaces: belocs-locales-bin,
 	libc6-amd64 [amd64],
@@ -297,7 +311,7 @@
 Depends: libc-bin (= ${binary:Version}), hurd (>= 20070606-1+SVN) [hurd-i386], libgcc1 [!hppa !m68k], libgcc2 [m68k], libgcc4 [hppa], tzdata
 Recommends: libc0.1-i686 [kfreebsd-i386], libc0.3-i686 [hurd-i386]
 Suggests: glibc-doc, debconf | debconf-2.0, locales [!hurd-i386]
-Provides: ${locale-compat:Depends}, libc6-i686 [i386], libc6-sparcv9b [sparc sparc64], multiarch-support
+Provides: ${locale-compat:Depends}, libc6-i686 [i386], libc6-sparcv9b [sparc sparc64]
 Conflicts: tzdata-etch, tzdata (<< 2007k-1), prelink (<< 0.0.20090925), belocs-locales-bin, libc6-i686 [i386]
 Replaces: belocs-locales-bin,
 	libc6-amd64 [amd64],
@@ -383,7 +397,7 @@
 Depends: libc-bin (= ${binary:Version}), hurd (>= 20070606-1+SVN) [hurd-i386], libgcc1 [!hppa !m68k], libgcc2 [m68k], libgcc4 [hppa], tzdata
 Recommends: libc0.1-i686 [kfreebsd-i386], libc0.3-i686 [hurd-i386]
 Suggests: glibc-doc, debconf | debconf-2.0, locales [!hurd-i386]
-Provides: ${locale-compat:Depends}, libc6-i686 [i386], libc6-sparcv9b [sparc sparc64], multiarch-support
+Provides: ${locale-compat:Depends}, libc6-i686 [i386], libc6-sparcv9b [sparc sparc64]
 Conflicts: tzdata-etch, tzdata (<< 2007k-1), prelink (<< 0.0.20090925), belocs-locales-bin, libc6-i686 [i386]
 Replaces: belocs-locales-bin,
 	libc6-amd64 [amd64],
 
=== modified file 'debian/control.in/libc'
--- debian/control.in/libc	2011-03-09 01:04:13 +0000
+++ debian/control.in/libc	2011-03-20 21:42:49 +0000
@@ -6,7 +6,7 @@
 Depends: libc-bin (= ${binary:Version}), hurd (>= 20070606-1+SVN) [hurd-i386], libgcc1 [!hppa !m68k], libgcc2 [m68k], libgcc4 [hppa], tzdata
 Recommends: libc0.1-i686 [kfreebsd-i386], libc0.3-i686 [hurd-i386]
 Suggests: glibc-doc, debconf | debconf-2.0, locales [!hurd-i386]
-Provides: ${locale-compat:Depends}, libc6-i686 [i386], libc6-sparcv9b [sparc sparc64], multiarch-support
+Provides: ${locale-compat:Depends}, libc6-i686 [i386], libc6-sparcv9b [sparc sparc64]
 Conflicts: tzdata-etch, tzdata (<< 2007k-1), prelink (<< 0.0.20090925), belocs-locales-bin, libc6-i686 [i386]
 Replaces: belocs-locales-bin,
 	libc6-amd64 [amd64],
 
=== modified file 'debian/control.in/main'
--- debian/control.in/main	2011-03-15 16:44:57 +0000
+++ debian/control.in/main	2011-03-20 21:42:49 +0000
@@ -117,3 +117,17 @@
  query. You should install this package only if you use
  slow Services like LDAP, NIS or NIS+
 
+Package: multiarch-support
+Architecture: any
+Multi-Arch: foreign
+Depends: libc6 (>= 2.3.6-2) [!any-i386 !alpha !ia64 !hurd-any !kfreebsd-any],
+         libc6.1 (>= 2.3.6-2) [alpha ia64],
+         libc0.3 (>= 2.3.6-2) [hurd-any],
+         libc0.1 (>= 2.3.6-2) [kfreebsd-any],
+         libc6 (>= 2.13-0ubuntu6) [any-i386]
+Priority: standard
+Description: Transitional package to ensure multiarch compatibility
+ This is a transitional package used to ensure multiarch support is present
+ in ld.so before unpacking libraries to the multiarch directories.  It can
+ be removed once nothing on the system depends on it.
+
 
=== modified file 'debian/rules'
--- debian/rules	2011-03-09 01:18:54 +0000
+++ debian/rules	2011-03-20 21:42:49 +0000
@@ -151,7 +151,7 @@
   DEB_INDEP_REGULAR_PACKAGES =
   DEB_UDEB_PACKAGES =
 else
-  DEB_ARCH_REGULAR_PACKAGES = $(libc) $(libc)-dev $(libc)-dbg $(libc)-prof $(libc)-pic libc-bin libc-dev-bin
+  DEB_ARCH_REGULAR_PACKAGES = $(libc) $(libc)-dev $(libc)-dbg $(libc)-prof $(libc)-pic libc-bin libc-dev-bin multiarch-support
   DEB_INDEP_REGULAR_PACKAGES = glibc-doc eglibc-source
   DEB_UDEB_PACKAGES = $(libc)-udeb libnss-dns-udeb libnss-files-udeb
 endif