Bug#1017979: mozjs91: FTBFS on armel with gcc 12: multiple definition of `__sync_fetch_and_add_4' etc.

[Simon McVittie]

Control: tags -1 + patch

On Tue, 23 Aug 2022 at 21:39:50 +0100, Simon McVittie wrote:
> On Tue, 23 Aug 2022 at 13:23:30 +0100, Simon McVittie wrote:
> > The final link fails with multiple definitions of the various atomic
> > builtins:
> > 
> > > (.text+0x0): multiple definition of `__sync_fetch_and_add_4'; /home/smcv/mozjs91-armel/debian/build/armv5te-unknown-linux-gnueabi/release/libjsrust.a(compiler_builtins-23c2fc8f8ef06d87.compiler_builtins.bdb7b41d-cgu.153.rcgu.o):/usr/src/rustc-1.59.0/vendor/compiler_builtins/src/arm_linux.rs:94: first defined here
> 
> Reported upstream as https://bugzilla.mozilla.org/show_bug.cgi?id=1786623

Workaround: link with -Wl,--allow-multiple-definition (thanks to Adrian
Bunk).

I think we're more likely to replace mozjs91 in gjs' dependencies with
mozjs102 and remove mozjs91 than we are to fix mozjs91, but I'm mentioning
this here in case it becomes necessary to use mozjs91 for some reason.
Linking with -Wl,--allow-multiple-definition seems like a less bad
workaround than using a non-default gcc.

    smcv