ci/docs: Build and check powerpc64le-unknown-linux-musl

Now that all of the issues with powerpc64 + musl are resolved, let's
make sure it won't regress in the future and also build the
documentation for it.

Signed-off-by: Jens Reidel <adrian@travitia.xyz>

Author: Gelbpunkt

.github/workflows/ci.yaml

@@ -188,6 +188,7 @@ jobs:
           - loongarch64-unknown-linux-musl
           - powerpc64-unknown-linux-gnu
           - powerpc64le-unknown-linux-gnu
+          - powerpc64le-unknown-linux-musl
           - riscv64gc-unknown-linux-gnu
           - s390x-unknown-linux-gnu
           - wasm32-unknown-emscripten
@@ -222,6 +223,9 @@ jobs:
           - target: loongarch64-unknown-linux-musl
             env:
               RUST_LIBC_UNSTABLE_MUSL_V1_2_3: 1
+          - target: powerpc64le-unknown-linux-musl
+            env:
+              RUST_LIBC_UNSTABLE_MUSL_V1_2_3: 1
           # FIXME(ppc): SIGILL running tests, see
           # https://github.com/rust-lang/libc/pull/4254#issuecomment-2636288713
           # - target: powerpc-unknown-linux-gnu

Cargo.toml

@@ -78,6 +78,7 @@ targets = [
     "powerpc64-unknown-linux-gnu",
     "powerpc64-wrs-vxworks",
     "powerpc64le-unknown-linux-gnu",
+    "powerpc64le-unknown-linux-musl",
     "riscv32gc-unknown-linux-gnu",
     "riscv32i-unknown-none-elf",
     "riscv32imac-unknown-none-elf",

ci/docker/powerpc64le-unknown-linux-musl/Dockerfile

@@ -0,0 +1,15 @@
+FROM ubuntu:24.10
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+  gcc make libc6-dev git curl ca-certificates \
+  gcc-powerpc64le-linux-gnu qemu-user xz-utils patch rsync
+
+COPY install-musl.sh /
+RUN /install-musl.sh powerpc64le
+
+# FIXME: shouldn't need the `-lgcc` here, shouldn't that be in std?
+ENV PATH=$PATH:/musl-powerpc64/bin:/rust/bin \
+    CC_powerpc64le_unknown_linux_musl=musl-gcc \
+    RUSTFLAGS='-Clink-args=-lgcc -L /musl-powerpc64/lib' \
+    CARGO_TARGET_POWERPC64LE_UNKNOWN_LINUX_MUSL_LINKER=musl-gcc \
+    CARGO_TARGET_POWERPC64LE_UNKNOWN_LINUX_MUSL_RUNNER="qemu-ppc64le -L /musl-powerpc64"

ci/install-musl.sh

@@ -68,6 +68,13 @@ case ${1} in
           ./configure --prefix="/musl-${musl_arch}" --enable-wrapper=yes
         make install -j4
         ;;
+    powerpc64*)
+        musl_arch=powerpc64
+        kernel_arch=powerpc
+        CC="${1}-linux-gnu-gcc" CFLAGS="-mlong-double-64" \
+          ./configure --prefix="/musl-${musl_arch}" --enable-wrapper=yes
+        make install -j4
+        ;;
     *)
         echo "Unknown target arch: \"${1}\""
         exit 1

ci/verify-build.sh

@@ -161,11 +161,14 @@ x86_64-unknown-linux-musl \
 x86_64-unknown-netbsd \
 "
 
+# FIXME(powerpc64le): powerpc64le-unknown-linux-musl is tier 2 since 1.85 and
+# can be moved to rust_linux_targets once MSRV is increased
 rust_nightly_linux_targets="\
 aarch64-unknown-fuchsia \
 armv5te-unknown-linux-gnueabi \
 armv5te-unknown-linux-musleabi \
 i686-pc-windows-gnu \
+powerpc64le-unknown-linux-musl \
 riscv64gc-unknown-linux-gnu \
 x86_64-fortanix-unknown-sgx \
 x86_64-pc-solaris \