Heads up: F21 LLVM rebase

Michael DePaulo mikedep333 at gmail.com
Sat Dec 13 12:56:17 UTC 2014


On Fri, Dec 12, 2014 at 7:51 PM, Kevin Kofler <kevin.kofler at chello.at> wrote:
> Michael DePaulo wrote:
>> I too come from an Ubuntu/Debian background. Like other major pieces
>> of software, Ubuntu and Debian both make multiple 2.x or 3.x versions
>> of LLVM available for each release of  their OS. They do the
>> following:
>> 1. The major version is specified in the package name. For example,
>> "llvm-3.4" and "llvm-3.5" are the names of separate packages. The
>> actual package versions are like "3.4.2-13" & "3.5-6" respectively
>>
>> 2. The package "llvm" is a small package that depends on the
>> recommended major version for developers. For example, in Jessie, 3.5
>> is the recommended major version, and Jessie "llvm" contains symlinks
>> such as:
>> /usr/bin/llvm-extract -> /usr/bin/llvm-extract-3.5
>>
>> Would Fedora permit someone like myself to contribute an LLVM
>> packaging scheme like that?
>
> That would NOT be a good idea, for a simple reason: The version of LLVM Mesa
> (i.e., libGL) links ends up linked into MANY executables. If you link some
> other library against some other version of LLVM, and then an application
> ends up directly or indirectly linking both that library and libGL, it ends
> up indirectly linking the 2 incompatible versions of LLVM and crashing. We
> have already had this happen, and other distributions too, see e.g.:
> http://www.valdyas.org/fading/index.cgi/2011/10/08#llvm
> and still, months later (when it was already long fixed in Fedora by using a
> common shared LLVM, but apparently not on some other distributions):
> http://mail.kde.org/pipermail/kimageshop/2012-September/011387.html
>
> (Now, to be fair, it turns out that OpenGTL has since been removed from
> Fedora because Krita no longer uses it, but the exact same problem can
> happen with any of the other consumers of LLVM.)
>
> There can be only one version of LLVM in the whole distribution at a time.
>
> This topic has already come up several times on this mailing list (basically
> each time such a rebase was done), please read the archives, e.g., this
> thread:
> https://lists.fedoraproject.org/pipermail/devel/2014-March/197227.html
> and my reply to a proposal essentially identical to yours:
> https://lists.fedoraproject.org/pipermail/devel/2014-March/197278.html
>
>         Kevin Kofler

Understood, sorry for not searching the archives.

-Mike


More information about the devel mailing list