fix(ci): use musl-gcc like xlings project (self-contained sysroot)

Follow the exact same toolchain approach as openxlings/xlings CI:
- Linux: musl-gcc 15.1.0 with --sdk/--cross/--cc/--cxx absolute paths
- macOS: llvm 20.1.7 with --toolchain=llvm --sdk/--cc/--cxx
- Windows: MSVC auto-detected

musl-gcc bundles its own libc so no system crt1.o/stdio.h needed.

Author: Sunrisepeak

.github/workflows/ci.yml

@@ -33,14 +33,12 @@ jobs:
       - name: Detect changed packages
         id: detect
         run: |
-          # Determine the base ref for comparison
           if [ "${{ github.event_name }}" = "pull_request" ]; then
             BASE="${{ github.event.pull_request.base.sha }}"
           else
             BASE="${{ github.event.before }}"
           fi
 
-          # Check if CI config itself changed — if so, build all
           CI_CHANGED=$(git diff --name-only "$BASE" HEAD -- .github/ .xlings.json || true)
           if [ -n "$CI_CHANGED" ]; then
             echo "build_all=true" >> "$GITHUB_OUTPUT"
@@ -49,20 +47,14 @@ jobs:
             echo "build_all=false" >> "$GITHUB_OUTPUT"
           fi
 
-          # Collect changed package names from packages/ and tests/ directories
           CHANGED_DIRS=$(git diff --name-only "$BASE" HEAD -- packages/ tests/ | \
             sed -n 's|^packages/./\([^/]*\)/.*|\1|p; s|^tests/./\([^/]*\)/.*|\1|p' | \
             sort -u)
 
-          # Build JSON array of changed packages
           JSON="["
           FIRST=true
           for pkg in $CHANGED_DIRS; do
-            if [ "$FIRST" = true ]; then
-              FIRST=false
-            else
-              JSON="$JSON,"
-            fi
+            if [ "$FIRST" = true ]; then FIRST=false; else JSON="$JSON,"; fi
             JSON="$JSON\"$pkg\""
           done
           JSON="$JSON]"
@@ -86,54 +78,56 @@ jobs:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/setup-toolchain
 
+      # --- Configure (same pattern as openxlings/xlings CI) ---
+
       - name: Configure (linux)
         if: runner.os == 'Linux'
         working-directory: tests
         run: |
-          GCC_VERSION=$(python3 -c "import json; d=json.load(open('../.xlings.json')); print(d['workspace']['gcc']['linux'])")
-          GCC_BIN="$HOME/.xlings/data/xpkgs/xim-x-gcc/${GCC_VERSION}/bin"
-          echo "Using gcc ${GCC_VERSION} from ${GCC_BIN}"
-          "${GCC_BIN}/gcc" --version | head -1
+          MUSL_GCC_VERSION=$(python3 -c "import json; d=json.load(open('../.xlings.json')); print(d['workspace']['musl-gcc']['linux'])")
+          MUSL_SDK="$HOME/.xlings/data/xpkgs/xim-x-musl-gcc/${MUSL_GCC_VERSION}"
+          echo "Using musl-gcc ${MUSL_GCC_VERSION} from ${MUSL_SDK}"
+          "${MUSL_SDK}/bin/x86_64-linux-musl-gcc" --version | head -1
 
-          # xlings gcc needs system sysroot for headers and CRT files
-          export LIBRARY_PATH="/usr/lib/x86_64-linux-gnu:/usr/lib:/lib/x86_64-linux-gnu"
-          export C_INCLUDE_PATH="/usr/include:/usr/include/x86_64-linux-gnu"
-          export CPLUS_INCLUDE_PATH="/usr/include:/usr/include/x86_64-linux-gnu"
-          export PATH="${GCC_BIN}:$PATH"
-
-          xmake f -P . -y -vv
+          xmake f -P . -y -vv \
+            --sdk="${MUSL_SDK}" \
+            --cross=x86_64-linux-musl- \
+            --cc="${MUSL_SDK}/bin/x86_64-linux-musl-gcc" \
+            --cxx="${MUSL_SDK}/bin/x86_64-linux-musl-g++"
 
       - name: Configure (macos)
         if: runner.os == 'macOS'
         working-directory: tests
         run: |
           LLVM_VERSION=$(python3 -c "import json; d=json.load(open('../.xlings.json')); print(d['workspace']['llvm']['macosx'])")
-          LLVM_BIN="$HOME/.xlings/data/xpkgs/xim-x-llvm/${LLVM_VERSION}/bin"
-          echo "Using llvm ${LLVM_VERSION} from ${LLVM_BIN}"
-          "${LLVM_BIN}/clang" --version | head -1
+          LLVM_SDK="$HOME/.xlings/data/xpkgs/xim-x-llvm/${LLVM_VERSION}"
+          echo "Using llvm ${LLVM_VERSION} from ${LLVM_SDK}"
+          "${LLVM_SDK}/bin/clang" --version | head -1
 
-          export PATH="${LLVM_BIN}:$PATH"
-          xmake f -P . -y -vv --toolchain=llvm
+          xmake f -P . -y -vv \
+            --toolchain=llvm \
+            --sdk="${LLVM_SDK}" \
+            --cc="${LLVM_SDK}/bin/clang" \
+            --cxx="${LLVM_SDK}/bin/clang++"
 
       - name: Configure (windows)
         if: runner.os == 'Windows'
         working-directory: tests
         run: xmake f -P . -y -vv
 
+      # --- Build and test ---
+
       - name: Build and test (unix)
         if: runner.os != 'Windows'
         working-directory: tests
         env:
           BUILD_ALL: ${{ needs.detect-changes.outputs.build_all }}
           CHANGED_PACKAGES: ${{ needs.detect-changes.outputs.packages }}
         run: |
-          # Put correct compiler on PATH and set system paths for xmake subprocesses
+          # Same compiler PATH as configure step
           if [ "$(uname)" = "Linux" ]; then
-            GCC_VERSION=$(python3 -c "import json; d=json.load(open('../.xlings.json')); print(d['workspace']['gcc']['linux'])")
-            export PATH="$HOME/.xlings/data/xpkgs/xim-x-gcc/${GCC_VERSION}/bin:$PATH"
-            export LIBRARY_PATH="/usr/lib/x86_64-linux-gnu:/usr/lib:/lib/x86_64-linux-gnu"
-            export C_INCLUDE_PATH="/usr/include:/usr/include/x86_64-linux-gnu"
-            export CPLUS_INCLUDE_PATH="/usr/include:/usr/include/x86_64-linux-gnu"
+            MUSL_GCC_VERSION=$(python3 -c "import json; d=json.load(open('../.xlings.json')); print(d['workspace']['musl-gcc']['linux'])")
+            export PATH="$HOME/.xlings/data/xpkgs/xim-x-musl-gcc/${MUSL_GCC_VERSION}/bin:$PATH"
           else
             LLVM_VERSION=$(python3 -c "import json; d=json.load(open('../.xlings.json')); print(d['workspace']['llvm']['macosx'])")
             export PATH="$HOME/.xlings/data/xpkgs/xim-x-llvm/${LLVM_VERSION}/bin:$PATH"
@@ -156,12 +150,10 @@ jobs:
             echo "Building changed targets: $TARGETS"
           fi
 
-          # Build and run each target
           for target in $TARGETS; do
             echo "=== Building $target ==="
             xmake build -P . -y "$target"
 
-            # llmapi requires API key, only build don't run
             if [ "$target" = "llmapi_test" ]; then
               echo "Skipping run for $target (requires API key)"
               continue
@@ -182,7 +174,6 @@ jobs:
           BUILD_ALL: ${{ needs.detect-changes.outputs.build_all }}
           CHANGED_PACKAGES: ${{ needs.detect-changes.outputs.packages }}
         run: |
-          # Collect test targets
           $targets = @()
           if ($env:BUILD_ALL -eq "true") {
             $targets = Get-ChildItem -Recurse -Filter "xmake.lua" -Path "*/*" |

.xlings.json

@@ -1,7 +1,7 @@
 {
   "workspace": {
     "xmake": "3.0.7",
-    "gcc": { "linux": "15.1.0" },
+    "musl-gcc": { "linux": "15.1.0" },
     "llvm": { "macosx": "20.1.7" }
   }
 }