Test a few tier 3 targets

.github/workflows/ci.yaml

@@ -277,6 +277,66 @@ jobs:
           path: ${{ env.ARCHIVE_PATH }}
           retention-days: 5
 
+  test_tier3:
+    name: Test tier3
+    #needs: [test_tier2, style_check]
+    runs-on: ubuntu-24.04
+    strategy:
+      fail-fast: true
+      max-parallel: 12
+      matrix:
+        target:
+          # We test a handful of tier 3 targets that are known to be well-maintained
+          #- mips64-unknown-linux-muslabi64
+          #- powerpc64-unknown-linux-musl
+          #- riscv64gc-unknown-linux-musl
+          - s390x-unknown-linux-musl
+        include:
+          #- target: mips64-unknown-linux-muslabi64
+          #  env:
+          #    RUST_LIBC_UNSTABLE_MUSL_V1_2_3: 1
+          #- target: powerpc64-unknown-linux-musl
+          #  env:
+          #    RUST_LIBC_UNSTABLE_MUSL_V1_2_3: 1
+          #- target: riscv64gc-unknown-linux-musl
+          #  env:
+          #    RUST_LIBC_UNSTABLE_MUSL_V1_2_3: 1
+          - target: s390x-unknown-linux-musl
+            env:
+              RUST_LIBC_UNSTABLE_MUSL_V1_2_3: 1
+    timeout-minutes: 25
+    env:
+      INSTALL_RUST_SRC: 1
+      LIBC_CI_ZBUILD_STD: 1
+      TARGET: ${{ matrix.target }}
+    steps:
+      - uses: actions/checkout@v5
+      - name: Setup Rust toolchain
+        run: ./ci/install-rust.sh
+      - uses: Swatinem/rust-cache@v2
+        with:
+          key: ${{ matrix.target }}
+      - name: Add matrix env variables to the environment
+        if: matrix.env
+        run: |
+          echo '${{ toJson(matrix.env) }}' |
+            jq -r 'to_entries | map("\(.key)=\(.value|tostring)") | .[]' >>$GITHUB_ENV
+        shell: bash
+
+      - name: Execute run-docker.sh
+        run: ./ci/run-docker.sh ${{ matrix.target }}
+
+      - name: Create CI artifacts
+        id: create_artifacts
+        if: always()
+        run: ./ci/create-artifacts.py
+      - uses: actions/upload-artifact@v4
+        if: always() && steps.create_artifacts.outcome == 'success'
+        with:
+          name: ${{ env.ARCHIVE_NAME }}-${{ matrix.target }}${{ matrix.artifact-tag && format('-{0}', matrix.artifact-tag) }}
+          path: ${{ env.ARCHIVE_PATH }}
+          retention-days: 5
+
   test_tier2_vm:
     name: Test tier2 VM
     needs: [test_tier1, style_check]

ci/docker/s390x-unknown-linux-musl/Dockerfile

@@ -1,18 +1,29 @@
 FROM ubuntu:25.04
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
-        curl ca-certificates \
-        gcc \
-        gcc-s390x-linux-gnu \
-        qemu-user \
-        xz-utils patch rsync
+  gcc make libc6-dev git curl ca-certificates \
+  gcc-s390x-linux-gnu qemu-user xz-utils patch rsync
+
+# Set up an Alpine sysroot for acquiring libgcc and libgcc_s
+RUN curl https://repo.chimera-linux.org/apk/3.0.0_rc4-r2/apk-x86_64.static -o /usr/bin/apk && \
+  chmod +x /usr/bin/apk && \
+  mkdir /alpine-sysroot && \
+  apk \
+    --arch s390x \
+    --root /alpine-sysroot \
+    --repository https://dl-cdn.alpinelinux.org/alpine/v3.22/main \
+    add \
+    --initdb \
+    --allow-untrusted \
+    --no-scripts \
+    alpine-baselayout libgcc
 
 COPY install-musl.sh /
 RUN /install-musl.sh s390x
 
 # FIXME: shouldn't need the `-lgcc` here, shouldn't that be in std?
-ENV CARGO_TARGET_S390X_UNKNOWN_LINUX_GNU_LINKER=s390x-linux-gnu-gcc \
-    CARGO_TARGET_S390X_UNKNOWN_LINUX_GNU_RUNNER="qemu-s390x -L /musl-s390x" \
-    CC_s390x_unknown_linux_gnu=musl-gcc \
-    RUSTFLAGS='-Clink-args=-lgcc -L /musl-s390x/lib' \
-    PATH=$PATH:/musl-s390x/bin:/rust/bin
+ENV PATH=$PATH:/musl-s390x/bin:/rust/bin \
+    CC_s390x_unknown_linux_musl=musl-gcc \
+    RUSTFLAGS='-Clink-args=-lgcc -L/alpine-sysroot/usr/lib -L /musl-s390x/lib' \
+    CARGO_TARGET_S390X_UNKNOWN_LINUX_MUSL_LINKER=musl-gcc \
+    CARGO_TARGET_S390X_UNKNOWN_LINUX_MUSL_RUNNER="qemu-s390x -L /musl-s390x"

ci/install-rust.sh

@@ -27,14 +27,12 @@ rustup set profile minimal
 rustup update --force "$toolchain" --no-self-update
 rustup default "$toolchain"
 
-if [ -n "${TARGET:-}" ]; then
-    echo "Install target"
-    rustup target add "$TARGET"
-fi
-
 if [ -n "${INSTALL_RUST_SRC:-}" ]; then
     echo "Install rust-src"
     rustup component add rust-src
+elif [ -n "${TARGET:-}" ]; then
+    echo "Install target"
+    rustup target add "$TARGET"
 fi
 
 if [ "$os" = "windows" ]; then

ctest/src/macro_expansion.rs

@@ -3,7 +3,7 @@ use std::fs::canonicalize;
 use std::path::Path;
 use std::process::Command;
 
-use crate::{EDITION, Result};
+use crate::{EDITION, GenerationError, Result};
 
 /// Use rustc to expand all macros and pretty print the crate into a single file.
 pub fn expand<P: AsRef<Path>>(
@@ -12,10 +12,13 @@ pub fn expand<P: AsRef<Path>>(
     target: String,
 ) -> Result<String> {
     let rustc = env::var("RUSTC").unwrap_or_else(|_| String::from("rustc"));
+    let out_dir =
+        env::var("OUT_DIR").map_err(|_| GenerationError::EnvVarNotFound("OUT_DIR".to_string()))?;
 
     let mut cmd = Command::new(rustc);
     cmd.env("RUSTC_BOOTSTRAP", "1")
         .arg("-Zunpretty=expanded")
+        .arg(format!("-L{out_dir}/../../../deps"))
         .arg("--edition")
         .arg(EDITION) // By default, -Zunpretty=expanded uses 2015 edition.
         .arg(canonicalize(crate_path)?);