perf(ci): cut CI wall clock from ~50m to ~14m

.github/workflows/external-tests.yml

@@ -23,12 +23,23 @@ env:
   CARGO_PROFILE_RELEASE_LTO: thin
   CARGO_PROFILE_RELEASE_CODEGEN_UNITS: 16
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' && !startsWith(github.ref, 'refs/tags/') }}
+
 jobs:
   lua-tests:
     name: e2e (${{ matrix.os }})
     runs-on: ${{ matrix.os }}
     # e2e tests could be flaky on CI so we do not block release creation if they failed
     continue-on-error: ${{ github.ref == 'refs/heads/main' && github.event_name == 'push' }}
+    # alpine-musl installs rust via apk and has no sccache, so keep this scoped.
+    env:
+      SCCACHE_GHA_ENABLED: "true"
+      RUSTC_WRAPPER: sccache
+      # fff-search alone exceeds the 600s default on windows, and the server
+      # sees no new requests while it compiles, so it would idle out mid-unit.
+      SCCACHE_IDLE_TIMEOUT: "0"
     strategy:
       fail-fast: false
       matrix:
@@ -53,10 +64,20 @@ jobs:
           cache-key: "v2-lua-e2e"
           rustflags: ""
 
+      - name: Setup sccache
+        uses: mozilla-actions/sccache-action@v0.0.11
+        with:
+          version: v0.17.0
+
       - name: Build Rust binary
         shell: bash
         run: make build-e2e
 
+      - name: sccache stats
+        if: always()
+        shell: bash
+        run: sccache --show-stats
+
       - name: Verify Windows DLL has no unexpected dependencies
         if: matrix.os == 'windows-latest'
         shell: pwsh

.github/workflows/lua.yml

@@ -12,6 +12,10 @@ on:
       - '**.md'
       - 'doc/**'
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' && !startsWith(github.ref, 'refs/tags/') }}
+
 jobs:
   lua-ls:
     name: lua-language-server type check

.github/workflows/nix.yml

@@ -12,6 +12,10 @@ on:
       - '**.md'
       - 'doc/**'
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' && !startsWith(github.ref, 'refs/tags/') }}
+
 jobs:
   check:
     runs-on: ubuntu-22.04

.github/workflows/python.yml

@@ -17,6 +17,15 @@ env:
   MACOSX_DEPLOYMENT_TARGET: "13.0"
   CARGO_PROFILE_RELEASE_LTO: thin
   CARGO_PROFILE_RELEASE_CODEGEN_UNITS: 16
+  SCCACHE_GHA_ENABLED: "true"
+  RUSTC_WRAPPER: sccache
+  # fff-search alone exceeds the 600s default on windows, and the server sees
+  # no new requests while it compiles, so it would idle out mid-unit.
+  SCCACHE_IDLE_TIMEOUT: "0"
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' && !startsWith(github.ref, 'refs/tags/') }}
 
 jobs:
   test:
@@ -39,6 +48,11 @@ jobs:
           cache-on-failure: true
           cache-key: "v1-rust-python"
 
+      - name: Setup sccache
+        uses: mozilla-actions/sccache-action@v0.0.11
+        with:
+          version: v0.17.0
+
       - name: Setup uv
         uses: astral-sh/setup-uv@v5
         with:

.github/workflows/release.yaml

@@ -17,10 +17,18 @@ on:
 env:
   FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: true
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' && !startsWith(github.ref, 'refs/tags/') }}
+
 jobs:
   build-nvim:
     name: Build Neovim ${{ matrix.target }}
     runs-on: ${{ matrix.os }}
+    env:
+      SCCACHE_GHA_ENABLED: "true"
+      RUSTC_WRAPPER: sccache
+      SCCACHE_IDLE_TIMEOUT: "0"
     permissions:
       contents: read
       id-token: write
@@ -91,6 +99,11 @@ jobs:
         with:
           key: nvim-${{ matrix.target }}
 
+      - name: Setup sccache
+        uses: mozilla-actions/sccache-action@v0.0.11
+        with:
+          version: v0.17.0
+
       - name: Install Zig
         uses: mlugg/setup-zig@v2
         with:
@@ -146,6 +159,10 @@ jobs:
   build-c:
     name: Build C FFI ${{ matrix.target }}
     runs-on: ${{ matrix.os }}
+    env:
+      SCCACHE_GHA_ENABLED: "true"
+      RUSTC_WRAPPER: sccache
+      SCCACHE_IDLE_TIMEOUT: "0"
     permissions:
       contents: read
     strategy:
@@ -228,6 +245,11 @@ jobs:
         with:
           key: c-${{ matrix.target }}
 
+      - name: Setup sccache
+        uses: mozilla-actions/sccache-action@v0.0.11
+        with:
+          version: v0.17.0
+
       - name: Install Zig
         uses: mlugg/setup-zig@v2
         with:
@@ -294,6 +316,10 @@ jobs:
   build-mcp:
     name: Build MCP ${{ matrix.target }}
     runs-on: ${{ matrix.os }}
+    env:
+      SCCACHE_GHA_ENABLED: "true"
+      RUSTC_WRAPPER: sccache
+      SCCACHE_IDLE_TIMEOUT: "0"
     permissions:
       contents: read
     strategy:
@@ -344,6 +370,11 @@ jobs:
         with:
           key: mcp-${{ matrix.target }}
 
+      - name: Setup sccache
+        uses: mozilla-actions/sccache-action@v0.0.11
+        with:
+          version: v0.17.0
+
       - name: Install Zig
         uses: mlugg/setup-zig@v2
         with:

.github/workflows/rust.yml

@@ -17,6 +17,15 @@ env:
   # Ensure consistent macOS deployment target across all compiled objects
   # (Rust, cc-compiled C code, and Zig-compiled zlob) to avoid linker warnings
   MACOSX_DEPLOYMENT_TARGET: "13"
+  # RUSTC_WRAPPER is set per job, since cargo fmt runs without sccache.
+  SCCACHE_GHA_ENABLED: "true"
+  # fff-search alone exceeds the 600s default on windows, and the server sees
+  # no new requests while it compiles, so it would idle out mid-unit.
+  SCCACHE_IDLE_TIMEOUT: "0"
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' && !startsWith(github.ref, 'refs/tags/') }}
 
 jobs:
   test:
@@ -46,7 +55,14 @@ jobs:
           cache-key: "v1-rust"
           components: rustfmt, clippy
 
+      - name: Setup sccache
+        uses: mozilla-actions/sccache-action@v0.0.11
+        with:
+          version: v0.17.0
+
       - name: Run tests
+        env:
+          RUSTC_WRAPPER: sccache
         # fff-python requires full python o3 machinery which is very slow
         run: cargo test --no-default-features --features zlob --workspace --exclude fff-nvim --exclude fff-python
 
@@ -66,6 +82,7 @@ jobs:
       FFF_STRESS_CASES: "5"
       FFF_STRESS_MIN_OPS: "30"
       FFF_STRESS_MAX_OPS: "60"
+      RUSTC_WRAPPER: sccache
     steps:
       - uses: actions/checkout@v5
 
@@ -82,6 +99,11 @@ jobs:
           cache-key: "v1-rust-stress-${{ matrix.os }}"
           components: rustfmt, clippy
 
+      - name: Setup sccache
+        uses: mozilla-actions/sccache-action@v0.0.11
+        with:
+          version: v0.17.0
+
       - name: Stress test seeded
         shell: bash
         run: make test-stress-seeded
@@ -125,7 +147,14 @@ jobs:
           cache-on-failure: true
           cache-key: "v1-rust-i686"
 
+      - name: Setup sccache
+        uses: mozilla-actions/sccache-action@v0.0.11
+        with:
+          version: v0.17.0
+
       - name: Build fff-search for i686
+        env:
+          RUSTC_WRAPPER: sccache
         run: cargo build -p fff-search --target i686-unknown-linux-gnu
 
   fmt:
@@ -158,6 +187,13 @@ jobs:
         with:
           toolchain: stable
           components: clippy
-
+
+      - name: Setup sccache
+        uses: mozilla-actions/sccache-action@v0.0.11
+        with:
+          version: v0.17.0
+
       - name: Run clippy
+        env:
+          RUSTC_WRAPPER: sccache
         run: cargo clippy --no-default-features --features zlob -- -D warnings

.github/workflows/spelling.yaml

@@ -12,6 +12,10 @@ on:
 env:
   CLICOLOR: 1
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' && !startsWith(github.ref, 'refs/tags/') }}
+
 jobs:
   spelling:
     name: Spell Check with Typos

.github/workflows/stylua.yaml

@@ -20,6 +20,10 @@ on:
 env:
   CLICOLOR: 1
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' && !startsWith(github.ref, 'refs/tags/') }}
+
 jobs:
   stylua:
     name: Check lua files using Stylua

Makefile

@@ -123,7 +123,7 @@ SMOKE_BIN := $(TARGET_DIR)/fff_c_smoke
 SMOKE_SRC := crates/fff-c/tests/smoke.c
 SMOKE_INCLUDE := crates/fff-c/include
 
-test-c-smoke: build
+test-c-smoke: build-e2e
 	$(CC) $(CFLAGS) -I $(SMOKE_INCLUDE) -L $(TARGET_DIR) \
 		-Wl,-rpath,@loader_path/../target/release \
 		-Wl,-rpath,$$(pwd)/$(TARGET_DIR) \
@@ -136,7 +136,7 @@ test-c-api: test-c-smoke
 # neovim instance swallows internal crashes and doesn't rise the the error exiting silently
 # so check the stdout in case the sigsegv coming out of fff was printed (actual regression).
 # Output is streamed live via `tee`; pipefail (set above) propagates nvim's exit.
-test-lua: test-setup build
+test-lua: test-setup build-e2e
 	@logfile=$$(mktemp); \
 	trap 'rm -f "$$logfile"' EXIT; \
 	nvim --headless -u tests/minimal_init.lua \
@@ -148,7 +148,7 @@ test-lua: test-setup build
 		exit 1; \
 	fi
 
-test-lua-snap: test-setup build
+test-lua-snap: test-setup build-e2e
 	@logfile=$$(mktemp); \
 	trap 'rm -f "$$logfile"' EXIT; \
 	nvim --headless -u tests/minimal_init.lua \
@@ -164,13 +164,13 @@ test-version: test-setup
 	nvim --headless -u tests/minimal_init.lua \
 		-c "PlenaryBustedFile tests/version_spec.lua" 2>&1
 
-prepare-bun: build sync-js-api
+prepare-bun: build-e2e sync-js-api
 	mkdir -p packages/fff-bun/bin
 	cp target/release/libfff_c.dylib packages/fff-bun/bin/ 2>/dev/null || true; \
 	cp target/release/libfff_c.so packages/fff-bun/bin/ 2>/dev/null || true; \
 	cp target/release/fff_c.dll packages/fff-bun/bin/ 2>/dev/null || true
 
-prepare-node: build sync-js-api
+prepare-node: build-e2e sync-js-api
 	mkdir -p packages/fff-node/bin
 	cp target/release/libfff_c.dylib packages/fff-node/bin/ 2>/dev/null || true; \
 	cp target/release/libfff_c.so packages/fff-node/bin/ 2>/dev/null || true; \

crates/fff-core/Cargo.toml

@@ -11,7 +11,7 @@ workspace = true
 
 [lib]
 path = "src/lib.rs"
-crate-type = ["rlib", "staticlib", "cdylib"]
+crate-type = ["rlib"]
 
 [[bench]]
 name = "parse_bench"

tests/programmatic_search_spec.lua

@@ -218,7 +218,13 @@ describe('programmatic search APIs', function()
       local before = fff.content_search(marker)
       assert.are.equal(0, #before.items, 'marker leaked into primary fff tree')
 
-      local result = fff.content_search(marker, { cwd = sandbox_root })
+      -- Poll instead of asserting on the first grep: the index of the new root
+      -- can lag a mkdir by a few ms on CI, which flaked on linux too.
+      local result
+      vim.wait(2000, function()
+        result = fff.content_search(marker, { cwd = sandbox_root })
+        return #result.items > 0
+      end, 50)
       assert.is_true(#result.items > 0, 'cwd switch did not surface match from the new root')
     end)
   end)