x86_64-linux-musl targets do not support multilib layout as-is and usually expects libdir=lib. glibc target usually uses libdir=lib64.
In https://bugs.gentoo.org/675954 (also touched on https://gcc.gnu.org/PR90077) Gentoo discovered the following discrepancy when gcc is built with --disable-multilib: 1. --disable-multilib ../gcc/configure --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --target=x86_64-gentoo-linux-musl --disable-multilib $ gcc/xgcc -B. -print-multi-os-directory ../lib64 Wouldn't it be reasonable to have '.' instead of '../lib64' here? 2. --disable-multilib --with-multilib-list= ../gcc/configure --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --target=x86_64-gentoo-linux-musl --disable-multilib --with-multilib-list= $ gcc/xgcc -B. -print-multi-os-directory . 3. --disable-multilib --with-multilib-list=m64 ../gcc/configure --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --target=x86_64-gentoo-linux-musl --disable-multilib --with-multilib-list=m64 $ gcc/xgcc -B. -print-multi-os-directory ../lib64 Currently Gentoo uses [3.] and experiences problems in 'meson' build systems which extract libdir via 'gcc -print-multi-os-directory' and observed "lib" != "lib64" mismatch. I have a few questions: Q1. Are all [1.]/[2.]/[3.] behaviors correct and expected? Should '--with-multilib-list=' (empty) be always accompanied with '--disable-multilib' to avoid multi-os-dir=../lib64? Or should gcc be tweaked to disallow contradicting cases like [3.]? Q2. What is the best way for *-musl* targets to just default to 'lib' layout at least for explicit '--disable-multilib' case? Just advise users do [2.] or should gcc be tweaked? Q3. Is '--disable-multilib --with-multilib-list=m64' a sensible configuration at all? Should it be an equivalent of '--disable-multilib --with-multilib-list=' (multi-os-dir=.) with default m64 ABI? Or should it be an equivalent of '--enable-multilib' (multi-os-dir=../lib64) with default m64 ABI? Thank you! -- Sergei
