[builtins] Add -fPIC to the flags to build libgif

[jmcarcell]

-fPIC is in the source code flags (both in 5.2.2 and the latest version, 6.1.2) and is causing errors when building in the LCG stacks. The errors look like

/cvmfs/sft.cern.ch/lcg/releases/binutils/2.40-acaab/x86_64-el9/bin/ld: ..<path-to-libgif-static>: relocation R_X86_64_32 against `.rodata' can not be used when making a shared object; recompile with -fPIC
/cvmfs/sft.cern.ch/lcg/releases/binutils/2.40-acaab/x86_64-el9/bin/ld: failed to set dynamic section sizes: bad value

I have built on Alma 9 with GCC 14 and that doesn't appear with this change anymore. I think you didn't see it in your CI because there isn't a Linux version with this enabled.

[github-actions]

Test Results

    22 files      22 suites   3d 2h 47m 37s ⏱️
 3 807 tests  3 806 ✅ 1 💤 0 ❌
75 796 runs  75 787 ✅ 9 💤 0 ❌

Results for commit 1be66db.

[will-cern]

Hello!
Is it possible this flag needs adding in a few places? We are seeing the problem in our nightly build of ROOT master as well, but specific to lzma builtin

/opt/lcg/binutils/2.40-acaab/x86_64-el9/bin/ld: ../builtins/LZMA-prefix/lib/liblzma.a(common.c.o): relocation R_X86_64_32 against `.rodata' can not be used when making a shared object; recompile with -fPIC
/opt/lcg/binutils/2.40-acaab/x86_64-el9/bin/ld: failed to set dynamic section sizes: bad value`

see https://gitlab.cern.ch/atlas/StatAnalysis/-/jobs/71456550

Cheers,
Will

[dpiparo]

Thanks @jmcarcell . @will-cern apologies for the issues, this is all very new and we need to work on some rough angles. Thanks for the report.