librsvg-2.55.1 fails to build on powerpc-gentoo-linux-musl stating a crossbeam error: error[E0432]: unresolved imports core::sync::atomic::AtomicI64, core::sync::atomic::AtomicU64

[ernsteiswuerfel]

librsvg-2.54.x can be patched to run on powerpc-gentoo-linux-musl by adding

[target.powerpc-gentoo-linux-musl]
rustflags = ["--cfg", "crossbeam_no_atomic_64"]

to .cargo/config but on librsvg-2.55.x this is no longer possible. 2.55.1 build fails with following crossbeam error:

[...]
     Running `rustc --crate-name crossbeam_utils --edition=2018 /var/tmp/portage/gnome-base/librsvg-2.55.1/work/cargo_home/gentoo/crossbeam-utils-0.8.11/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata,link -C opt-level=3 -C embed-bitcode=no --cfg 'feature="default"' --cfg 'feature="once_cell"' --cfg 'feature="std"' -C metadata=650926ecf19e73c2 -C extra-filename=-650926ecf19e73c2 --out-dir /var/tmp/portage/gnome-base/librsvg-2.55.1/work/librsvg-2.55.1-.ppc/target/release/deps -L dependency=/var/tmp/portage/gnome-base/librsvg-2.55.1/work/librsvg-2.55.1-.ppc/target/release/deps --extern cfg_if=/var/tmp/portage/gnome-base/librsvg-2.55.1/work/librsvg-2.55.1-.ppc/target/release/deps/libcfg_if-8b0eed1ca9f18504.rmeta --extern once_cell=/var/tmp/portage/gnome-base/librsvg-2.55.1/work/librsvg-2.55.1-.ppc/target/release/deps/libonce_cell-5ba52b14be4f5b16.rmeta --cap-lints allow`
error[E0432]: unresolved imports `core::sync::atomic::AtomicI64`, `core::sync::atomic::AtomicU64`
  --> /var/tmp/portage/gnome-base/librsvg-2.55.1/work/cargo_home/gentoo/crossbeam-utils-0.8.11/src/lib.rs:79:49
   |
79 |             pub(crate) use core::sync::atomic::{AtomicI64, AtomicU64};
   |                                                 ^^^^^^^^^  ^^^^^^^^^ no `AtomicU64` in `sync::atomic`
   |                                                 |
   |                                                 no `AtomicI64` in `sync::atomic`
   |
help: a similar name exists in the module
   |
79 |             pub(crate) use core::sync::atomic::{AtomicI8, AtomicU64};
   |                                                 ~~~~~~~~
help: a similar name exists in the module
   |
79 |             pub(crate) use core::sync::atomic::{AtomicI64, AtomicU8};
   |                                                            ~~~~~~~~

error[E0412]: cannot find type `AtomicU64` in module `core::sync::atomic`
    --> /var/tmp/portage/gnome-base/librsvg-2.55.1/work/cargo_home/gentoo/crossbeam-utils-0.8.11/src/atomic/consume.rs:78:14
     |
78   |   impl_atomic!(AtomicU64, u64);
     |                ^^^^^^^^^ help: a struct with a similar name exists: `AtomicU16`

error[E0412]: cannot find type `AtomicI64` in module `core::sync::atomic`
    --> /var/tmp/portage/gnome-base/librsvg-2.55.1/work/cargo_home/gentoo/crossbeam-utils-0.8.11/src/atomic/consume.rs:80:14
     |
80   |   impl_atomic!(AtomicI64, i64);
     |                ^^^^^^^^^ help: a struct with a similar name exists: `AtomicI16`

Some errors have detailed explanations: E0412, E0432.
For more information about an error, try `rustc --explain E0412`.
error: could not compile `crossbeam-utils` due to 3 previous errors

Caused by:
  process didn't exit successfully: `rustc --crate-name crossbeam_utils --edition=2018 /var/tmp/portage/gnome-base/librsvg-2.55.1/work/cargo_home/gentoo/crossbeam-utils-0.8.11/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata,link -C opt-level=3 -C embed-bitcode=no --cfg 'feature="default"' --cfg 'feature="once_cell"' --cfg 'feature="std"' -C metadata=650926ecf19e73c2 -C extra-filename=-650926ecf19e73c2 --out-dir /var/tmp/portage/gnome-base/librsvg-2.55.1/work/librsvg-2.55.1-.ppc/target/release/deps -L dependency=/var/tmp/portage/gnome-base/librsvg-2.55.1/work/librsvg-2.55.1-.ppc/target/release/deps --extern cfg_if=/var/tmp/portage/gnome-base/librsvg-2.55.1/work/librsvg-2.55.1-.ppc/target/release/deps/libcfg_if-8b0eed1ca9f18504.rmeta --extern once_cell=/var/tmp/portage/gnome-base/librsvg-2.55.1/work/librsvg-2.55.1-.ppc/target/release/deps/libonce_cell-5ba52b14be4f5b16.rmeta --cap-lints allow` (exit status: 1)
make[2]: *** [Makefile:1554: librsvg_c_api.la] Error 101

Toolchain used is Rust 1.61, GCC 12.2, binutils 2.39, musl 1.2.3. Build is done natively on Gentoo powerpc-gentoo-linux-musl on a Talos II.
librsvg-2.55.1:20221107-074807.log

[taiki-e]

Should be fixed in #922.

[ernsteiswuerfel]

Many thanks! I'll report back shortly if this works with librsvg on powerpc as soon as I can test.