Bug 599684 – dev-util/cmake: find_library() lib32 logic doesn't work when Gentoo looks like Debian

• Status: RESOLVED NEEDINFO
• Product: Gentoo Linux

[Description Sebastian Pipping 2016-11-13 21:47:59 UTC]

Created attachment 453256 [details]
compressed build log

Hi!


My interpretation of the build log is that 64bit /usr/lib/libffi.so is used when linking a 32bit library:

# file -L /usr/lib/libffi.so
/usr/lib/libffi.so: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, stripped

Please see the log for details.

Best



Sebastian

[Comment 1 Michał Górny 2016-11-13 21:54:45 UTC]

What is your CMake version?

[Comment 2 Sebastian Pipping 2016-11-13 22:06:00 UTC]

(In reply to Michał Górny from comment #1)
> What is your CMake version?

3.6.3

[Comment 3 Michał Górny 2016-11-13 22:20:45 UTC]

That's weird. It seems that this CMake version has the lib32 patch. Are you sure you're not using a custom ebuild or sth?

[Comment 4 Sebastian Pipping 2016-11-13 22:58:36 UTC]

(In reply to Michał Górny from comment #3)
> That's weird. It seems that this CMake version has the lib32 patch. Are you
> sure you're not using a custom ebuild or sth?

Yes:


>>> Emerging (66 of 92) sys-devel/llvm-3.9.0-r1::gentoo
>>> Failed to emerge sys-devel/llvm-3.9.0-r1, Log file:
>>>  '/var/log/portage/logdir/sys-devel:llvm-3.9.0-r1:20161113-141526.log'
>>> Jobs: 65 of 92 complete, 1 failed               Load avg: 7.16, 9.06, 9.95
*** Resuming merge...

[Comment 5 Michał Górny 2016-11-14 08:07:22 UTC]

(In reply to Sebastian Pipping from comment #4)
> (In reply to Michał Górny from comment #3)
> > That's weird. It seems that this CMake version has the lib32 patch. Are you
> > sure you're not using a custom ebuild or sth?
> 
> Yes:
> 
> 
> >>> Emerging (66 of 92) sys-devel/llvm-3.9.0-r1::gentoo
> >>> Failed to emerge sys-devel/llvm-3.9.0-r1, Log file:
> >>>  '/var/log/portage/logdir/sys-devel:llvm-3.9.0-r1:20161113-141526.log'
> >>> Jobs: 65 of 92 complete, 1 failed               Load avg: 7.16, 9.06, 9.95
> *** Resuming merge...

I was actually asking about CMake. But I guess we'll need to dig into that deeper.

Could you start a new build, let it go past src_configure() and paste the 32-bit CMakeFiles/CMake{Output,Error}.*?

[Comment 6 Sebastian Pipping 2016-11-14 21:08:09 UTC]

Created attachment 453332 [details]
x86_32.x86/CMakeFiles/CMakeError.log.xz

[Comment 7 Sebastian Pipping 2016-11-14 21:08:35 UTC]

Created attachment 453334 [details]
x86_32.x86/CMakeFiles/CMakeOutput.log.xz

[Comment 8 Michał Górny 2016-11-14 21:46:43 UTC]

I'm sorry but I really see nothing obviously wrong here. It's clearly CMake's find_library() finding the wrong library.

Looking at the patch... do you happen to have /etc/debian_version in your system?

[Comment 9 Sebastian Pipping 2016-11-14 21:49:10 UTC]

(In reply to Michał Górny from comment #8)
> Looking at the patch... do you happen to have /etc/debian_version in your
> system?

Actually yes.  It's needed for www-client/chromium-bin-debian.

[Comment 10 Michał Górny 2016-11-14 21:57:38 UTC]

(In reply to Sebastian Pipping from comment #9)
> (In reply to Michał Górny from comment #8)
> > Looking at the patch... do you happen to have /etc/debian_version in your
> > system?
> 
> Actually yes.  It's needed for www-client/chromium-bin-debian.

Errr... then I'm afraid I can't help you. This file makes CMake believe it's running on Debian and lib32 isn't used on Debian.

Reassigning to CMake maintainers, in case they want to improve the find_library() logic. This probably also breaks Gentoo Prefix on Debian. Can't promise you they'll do anything about it though.

Your other option is to switch to the lib/lib64 layout (also called SYMLINK_LIB=no).

[Comment 11 Michał Górny 2016-11-14 22:00:18 UTC]

(In reply to Michał Górny from comment #10)
> Your other option is to switch to the lib/lib64 layout (also called
> SYMLINK_LIB=no).

Hmm, I actually may be wrong here. I suspect CMake may ignore lib64 as well when it's running Debian. Feel like multiarch? ;-)

[Comment 12 Sebastian Pipping 2016-11-14 23:10:11 UTC]

I found a way to patch use of /etc/debian_version out of www-client/chromium-bin-debian::betagarden now.

[Comment 13 Michael Palimaka (kensington) 2017-06-24 14:56:28 UTC]

From Modules/Platform/Linux.cmake:
# Debian has lib32 and lib64 paths only for compatibility so they should not be
# searched.
if(NOT CMAKE_CROSSCOMPILING AND EXISTS "/etc/debian_version")
  set_property(GLOBAL PROPERTY FIND_LIBRARY_USE_LIB32_PATHS FALSE)
  set_property(GLOBAL PROPERTY FIND_LIBRARY_USE_LIB64_PATHS FALSE)
endif()

It would be possible to fix this by patching in a conditional on CMAKE_GENTOO_BUILD, or reverting the property in our build rules file.

However, there's a few other place this check is used so I wonder if it will be worth the effort to maintain the patches or if it's better to just declare this configuration unsupported.

[Comment 14 Michael Palimaka (kensington) 2019-04-25 10:20:57 UTC]

I haven't heard anything else here for a long time, so feel free to reopen if some action does need to be taken.