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

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,