Error on stale entries in failing test files

.github/workflows/failures.yml

@@ -98,15 +98,29 @@ jobs:
       if: matrix.libgccjit_version.gcc != 'libgccjit12.so'
       id: tests
       run: |
-        ${{ matrix.libgccjit_version.env_extra }} ./y.sh test --release --clean --build-sysroot --test-failing-rustc ${{ matrix.libgccjit_version.extra }} 2>&1 | tee output_log
+        # Without this, `tee` masks the exit status of `y.sh test`.
+        set -o pipefail
+        status=0
+        ${{ matrix.libgccjit_version.env_extra }} ./y.sh test --release --clean --build-sysroot --test-failing-rustc ${{ matrix.libgccjit_version.extra }} 2>&1 | tee output_log || status=$?
+        # This suite runs the tests known to fail, so only a build system error must fail the job.
+        if [ "$status" -ne 0 ] && [ "$status" -ne 2 ]; then
+          exit "$status"
+        fi
         rg --text "test result" output_log >> $GITHUB_STEP_SUMMARY
 
     - name: Run failing ui pattern tests for ICE
       # FIXME: re-enable those tests for libgccjit 12.
       if: matrix.libgccjit_version.gcc != 'libgccjit12.so'
       id: ui-tests
       run: |
-        ${{ matrix.libgccjit_version.env_extra }} ./y.sh test --release --test-failing-ui-pattern-tests ${{ matrix.libgccjit_version.extra }} 2>&1 | tee output_log_ui
+        # Without this, `tee` masks the exit status of `y.sh test`.
+        set -o pipefail
+        status=0
+        ${{ matrix.libgccjit_version.env_extra }} ./y.sh test --release --test-failing-ui-pattern-tests ${{ matrix.libgccjit_version.extra }} 2>&1 | tee output_log_ui || status=$?
+        # This suite runs tests that fail, so only a build system error must fail the job here.
+        if [ "$status" -ne 0 ] && [ "$status" -ne 2 ]; then
+          exit "$status"
+        fi
         if grep -q "the compiler unexpectedly panicked" output_log_ui; then
           echo "Error: 'the compiler unexpectedly panicked' found in output logs. CI Error!!"
           exit 1

build_system/src/build.rs

@@ -132,6 +132,24 @@ pub fn build_sysroot(env: &HashMap<String, String>, config: &ConfigInfo) -> Resu
 
     // Builds libs
     let mut rustflags = env.get("RUSTFLAGS").cloned().unwrap_or_default();
+
+    // Record the sysroot sources under the path the `rust-src` component uses, which is where
+    // rustc looks for them to turn a sysroot span into `/rustc/$hash`. Without this, ui tests
+    // print the build path where they expect `$SRC_DIR`.
+    let sysroot_source_dir = lib_path.join("rustlib/src/rust/library");
+    rustflags.push_str(&format!(
+        " --remap-path-prefix={library_dir}={sysroot_source_dir}",
+        library_dir = std::path::absolute(&library_dir)
+            .map_err(|error| format!(
+                "Failed to get the absolute path of the sysroot sources: {error:?}"
+            ))?
+            .display(),
+        sysroot_source_dir = std::path::absolute(&sysroot_source_dir)
+            .map_err(|error| format!(
+                "Failed to get the absolute path of the sysroot sources: {error:?}"
+            ))?
+            .display(),
+    ));
     if config.sysroot_panic_abort {
         rustflags.push_str(" -Cpanic=abort -Zpanic-abort-tests");
     }

build_system/src/main.rs

@@ -112,6 +112,9 @@ fn main() {
         Command::CheckTodo => todo::run(),
     } {
         eprintln!("Command failed to run: {e}");
-        process::exit(1);
+        // CI needs to tell a build system error apart from the test failures some suites expect.
+        let exit_code =
+            if e == test::TESTS_FAILED_ERROR { test::TESTS_FAILED_EXIT_CODE } else { 1 };
+        process::exit(exit_code);
     }
 }