Bug#1131165: gcc-15 FTBFS for musl-linux-amd64

On 3/12/26 19:09, Helmut Grohne wrote:
> Source: gcc-15
> Severity: wishlist
> Tags: ftbfs
> X-Debbugs-Cc: [email protected],[email protected]
> User: [email protected]
> Usertags: amd64
> User: [email protected]
> Usertags: rebootstrap
> 
> Hi Matthias,
> 
> I attempted building gcc-15 for musl-linux-amd64. Doing so fails. The
> immediate reason is that gcc defaults to enabling multilib for the
> x86_64 (and other) CPUs and Debian's musl package does not build a i386
> multilib package (and other combinations). Hence the gcc build ends up
> missing C library parts and fails. I argue that enabling multilib on any
> but the existing combinations in release architectures is not useful.
> The gcc packaging actually does not consider any of the musl
> architectures to be multilib and $(biarch32) is not "yes" in a build.
> However, the architecture matching in rules2 does not cover musl and
> therefore --disable-multilib is not passed to configure. I suggest
> updating the architecture match to match by CPU rather than full
> architecture as that's how gcc upstream determines the default for
> multilib. I'm attaching a patch implementing this.

Is there any documentation for musl, which triplets and/or multiarch 
identifiers are used for these musl packages?