ci: test warm Linux Windows archive build

Cross-compile Windows test binaries on Linux with the xwin SDK cache restored, then run the archived tests across four Windows partitions.

Run the smaller ignored suite once on the last partition to test whether extra run-only shards improve wall time.

Author: claude

.github/workflows/ci.yml

@@ -133,11 +133,12 @@ jobs:
 
   # Windows tests are cross-compiled on a fast Linux runner with cargo-xwin
   # (clang-cl + lld-link against the xwin-downloaded MSVC CRT/Windows SDK)
-  # and packed into a portable nextest archive. The test-windows shards then
-  # only download the archive and run it — no Rust toolchain or compilation
-  # on the slow Windows runners. Windows e2e fixtures dominate wall-clock
-  # (60s per PTY step vs 20s on Unix), so the run is split across shards via
-  # nextest's count partitioning, which spreads tests round-robin.
+  # and packed into a portable nextest archive. The Windows runners then only
+  # download the archive and run it: no Rust toolchain or compilation on the
+  # slow runners. Four nextest partitions avoid most repeated setup while keeping
+  # enough parallelism for the Windows-heavy default test workload. The much
+  # smaller Node-backed ignored suite runs once in the last partition, avoiding
+  # a duplicate Windows Node setup.
   build-windows-tests:
     needs: detect-changes
     if: needs.detect-changes.outputs.code-changed == 'true'
@@ -174,7 +175,7 @@ jobs:
           tool: cargo-nextest,cargo-xwin
 
       # Downloading and unpacking the MSVC CRT/Windows SDK dominates this
-      # job's wall time (~10 minutes); the unpacked result is immutable for a
+      # job's wall time on a cold cache; the unpacked result is immutable for a
       # given manifest version, so cache it. Bump the key when bumping the
       # xwin version.
       - uses: actions/cache/restore@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
@@ -214,10 +215,10 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        partition: [1, 2, 3, 4, 5, 6]
+        partition: [1, 2, 3, 4]
     runs-on: windows-latest
     env:
-      PARTITION: count:${{ matrix.partition }}/6
+      PARTITION: count:${{ matrix.partition }}/4
     steps:
       - uses: taiki-e/checkout-action@7d1e50e93dc4fb3bba58f85018fadf77898aee8b # v1.4.2
 
@@ -243,11 +244,11 @@ jobs:
         run: cargo-nextest nextest run --archive-file windows-tests.tar.zst --workspace-remap . --partition "$PARTITION"
 
       - uses: oxc-project/setup-node@ab97f03642370d79a7e96dd286bd02a1be40e0ba # v1.3.0
+        if: matrix.partition == 4
 
-      # --no-tests=pass: a shard's partition of the (much smaller) ignored
-      # test set may legitimately come up empty.
       - name: Run ignored tests
-        run: cargo-nextest nextest run --archive-file windows-tests.tar.zst --workspace-remap . --partition "$PARTITION" --run-ignored ignored-only --no-tests pass
+        if: matrix.partition == 4
+        run: cargo-nextest nextest run --archive-file windows-tests.tar.zst --workspace-remap . --run-ignored ignored-only
 
   test-musl:
     needs: detect-changes

crates/fspy/tests/oxlint.rs

@@ -8,9 +8,7 @@ use test_log::test;
 /// Get the packages/tools/.bin directory path
 fn tools_bin_dir() -> std::path::PathBuf {
     // Resolve CARGO_MANIFEST_DIR at run time, not via `env!`: a compile-time
-    // path bakes in the build machine's checkout, which breaks when the test
-    // binary is cross-compiled and run on another machine (e.g. built on
-    // Linux with cargo-xwin, run on Windows from a nextest archive).
+    // path can point at a different checkout than the one executing the test.
     let manifest_dir = std::path::PathBuf::from(std::env::var_os("CARGO_MANIFEST_DIR").unwrap());
     manifest_dir
         .parent()