Bug#1111182: llvm-toolchain-19: please move /usr/lib/llvm* to a multi-arch co-installable location

[Simon McVittie]

Source: llvm-toolchain-19
Severity: wishlist
Control: clone -1 -2
Control: retitle -2 llvm-toolchain-20: please move /usr/lib/llvm* to a multi-arch co-installable location
Control: reassign -2 src:llvm-toolchain-20

Passing on a request from the developers of the FEX x86 emulator:

While building mixed-architecture software, they've been frustrated by 
the fact that files in /usr/lib/llvm-19 are not multi-arch 
co-installable, so on Debian/Ubuntu they can't build amd64 and i386 code 
that uses libLLVM (such as 64- and 32-bit versions of Mesa) without 
entering separate containers/chroots.

This affects llvm-{19,20}-dev and perhaps others.

I'm told that on other distributions like the Red Hat and Arch families, 
the equivalent of our /usr/lib/llvm-19 is something like 
/usr/lib{64,}/llvm (Red Hat) or /usr/lib{,32}/llvm (Arch). This suggests 
that on Debian, it should be possible to use our equivalent of lib64, 
/usr/lib/${DEB_HOST_MULTIARCH}/llvm-{19,20,...}, for a similar level of 
co-installability.

Thanks,
    smcv