[Fedora-packaging] llvm case study: yum's handling of newly-converted noarch subpackages

[Mamoru Tasaka]

Michel Alexandre Salim wrote, at 06/08/2010 05:12 PM +9:00:
> An LLVM user reported to me a problem updating LLVM (from the version
> in F13-updates to the version that is then in Koji), and I suggested
> that he filed a bug report.
>
> https://bugzilla.redhat.com/show_bug.cgi?id=600969
>
> In the discussion that follows, James Antill diagnosed the problem as
> due to llvm-doc being changed to be a noarch subpackage, as supported
> by RPM 4.7 and above, and thus when using yum to update from
> llvm-2.7-1 (with arched -doc) to 2.7-4 (noarch doc), llvm-2.7-1 causes
> llvm-2.7-1.i686 to be pulled in to satisfy the dependencies)
>
> To reproduce:
> - on an x86_64 system, yum install llvm-doc
> - Download llvm{,-doc} from Koji
> http://koji.fedoraproject.org/koji/buildinfo?buildID=176782
> - Try a yum localupdate or a yum localinstall
>
> The suggested fix by James, and by some folks on #fedora-devel, is to
> make the new -doc Obsoletes: the old doc. This, alas, does not quite
> work:
>
>
> http://koji.fedoraproject.org/koji/taskinfo?taskID=2236690
>
> - Download llvm-2.7-5 from the scratch builds above
> - Retry localupdate / localinstall
>
> the -doc update is considered but then dropped.
>
> Any idea how to fix this? We should probably add a section to the
> packaging guidelines, on how to migrate to noarch subpackages without
> breaking upgrade paths.
>
> Thanks,

Looks like that just yum must hanble {i686,x86_64,etc} <-> noarch
transition correctly (i.e. I will vote that this is a bug in yum).
My recognition is that rpm -Uvh handles this correctly.

Mamoru