chore(build): finish the .fbuild ratchet — baseline reaches zero

crates/fbuild-build-engine/src/compiler_tests.rs

@@ -36,7 +36,7 @@ async fn compile_path_contract_pairs_cwd_and_output_arg_for_282() {
     let workspace = tmp_canon.join("proj_for_282");
     let core = workspace
         .join(fbuild_paths::FBUILD_DIR_NAME)
-        .join("build")
+        .join(fbuild_paths::BUILD_DIR_NAME)
         .join("x")
         .join("quick")
         .join("core");

crates/fbuild-build/src/compile_many.rs

@@ -840,9 +840,17 @@ mod tests {
         // here that doesn't also update the orchestrators will silently
         // break the stage-1→stage-2 core/ handoff in FastLED/fbuild#335.
         let p = project_build_dir(Path::new("/tmp/sketch"), "uno", BuildProfile::Release);
-        assert!(p.ends_with("sketch/.fbuild/build/uno/release"));
+        assert!(p.ends_with(format!(
+            "sketch/{}/{}/uno/release",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        )));
         let q = project_build_dir(Path::new("/tmp/sketch"), "esp32s3", BuildProfile::Quick);
-        assert!(q.ends_with("sketch/.fbuild/build/esp32s3/quick"));
+        assert!(q.ends_with(format!(
+            "sketch/{}/{}/esp32s3/quick",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        )));
     }
 
     /// FastLED stages each board's project at

crates/fbuild-build/tests/avr_build.rs

@@ -122,7 +122,11 @@ async fn build_uno_minimal() {
     // `params.build_dir` is the resolved env-rooted dir per
     // `BuildLayout::resolve()`.
     let tmp = tempfile::TempDir::new().unwrap();
-    let build_dir = tmp.path().join(".fbuild/build/uno/release");
+    let build_dir = tmp.path().join(format!(
+        "{}/{}/uno/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
 
     let params = BuildParams {
         project_dir: project_dir.clone(),
@@ -210,7 +214,11 @@ async fn build_uno_minimal() {
 async fn compare_with_python_output() {
     let project_dir = home_dir().join("dev/fbuild/tests/uno_minimal");
 
-    let python_hex = project_dir.join(".fbuild/build/uno/release/firmware.hex");
+    let python_hex = project_dir.join(format!(
+        "{}/{}/uno/release/firmware.hex",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     if !python_hex.exists() {
         eprintln!(
             "SKIP: Python build output not found at {}",
@@ -222,7 +230,11 @@ async fn compare_with_python_output() {
 
     // Build with Rust
     let tmp = tempfile::TempDir::new().unwrap();
-    let build_dir = tmp.path().join(".fbuild/build/uno/release");
+    let build_dir = tmp.path().join(format!(
+        "{}/{}/uno/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
 
     let params = BuildParams {
         project_dir: project_dir.clone(),
@@ -317,7 +329,11 @@ void loop() {
     )
     .unwrap();
 
-    let build_dir = project_dir.join(".fbuild/build/uno/release");
+    let build_dir = project_dir.join(format!(
+        "{}/{}/uno/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     let params = BuildParams {
         project_dir: project_dir.to_path_buf(),
         env_name: "uno".to_string(),
@@ -438,7 +454,11 @@ fn stomp_mtimes(root: &Path, mtime: FileTime) {
 }
 
 fn fingerprint_path(project_dir: &Path) -> PathBuf {
-    project_dir.join(".fbuild/build/uno/release/build_fingerprint.json")
+    project_dir.join(format!(
+        "{}/{}/uno/release/build_fingerprint.json",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ))
 }
 
 /// RAII guard for an env var: sets it on construction, restores the previous
@@ -501,7 +521,11 @@ async fn cache_survives_tar_extract_uno() {
 
     let cold_result = under_test_timeout(orchestrator.build(&uno_build_params(
         &proj_a,
-        proj_a.join(".fbuild/build/uno/release"),
+        proj_a.join(format!(
+            "{}/{}/uno/release",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        )),
         true,
     )))
     .await
@@ -533,7 +557,11 @@ async fn cache_survives_tar_extract_uno() {
     // because of an orchestrator/fast-path bug unrelated to tar restoration.
     let same_project_warm = under_test_timeout(orchestrator.build(&uno_build_params(
         &proj_a,
-        proj_a.join(".fbuild/build/uno/release"),
+        proj_a.join(format!(
+            "{}/{}/uno/release",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        )),
         false,
     )))
     .await
@@ -564,8 +592,16 @@ async fn cache_survives_tar_extract_uno() {
         proj_b.display()
     );
     assert!(
-        proj_b.join(".fbuild/build").exists(),
-        "tar restore left no .fbuild/build/ at {}",
+        proj_b
+            .join(format!(
+                "{}/{}",
+                fbuild_paths::FBUILD_DIR_NAME,
+                fbuild_paths::BUILD_DIR_NAME
+            ))
+            .exists(),
+        "tar restore left no {}/{}/ at {}",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME,
         proj_b.display()
     );
     assert_ne!(
@@ -578,7 +614,11 @@ async fn cache_survives_tar_extract_uno() {
 
     let warm_result = under_test_timeout(orchestrator.build(&uno_build_params(
         &proj_b,
-        proj_b.join(".fbuild/build/uno/release"),
+        proj_b.join(format!(
+            "{}/{}/uno/release",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        )),
         false,
     )))
     .await

crates/fbuild-build/tests/clangd_check_parity.rs

@@ -154,7 +154,11 @@ async fn clangd_check_parity_uno() {
     install_test_compile_backend().await;
 
     let tmp = tempfile::TempDir::new().expect("tempdir");
-    let build_dir = tmp.path().join(".fbuild/build/uno/release");
+    let build_dir = tmp.path().join(format!(
+        "{}/{}/uno/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
 
     let params = BuildParams {
         project_dir: project_dir.clone(),

crates/fbuild-build/tests/compile_many_stage2_perf.rs

@@ -275,10 +275,13 @@ Compiled 5/26 files
 /// point) and embeds its head and tail so the failure is diagnosable after
 /// the TempDir is dropped — FastLED/fbuild#1346.
 fn stage2_failure_detail(r: &SketchResult) -> String {
-    let log_path = r
-        .log_path
-        .clone()
-        .unwrap_or_else(|| r.sketch.join(".fbuild/build/uno/release/compile_many.log"));
+    let log_path = r.log_path.clone().unwrap_or_else(|| {
+        r.sketch.join(format!(
+            "{}/{}/uno/release/compile_many.log",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        ))
+    });
     let log = fs::read_to_string(&log_path).unwrap_or_else(|e| {
         format!(
             "<compile_many.log unreadable at {}: {e}>",

crates/fbuild-build/tests/compile_many_two_stage.rs

@@ -98,8 +98,8 @@ impl SketchBuilder for MockBuilder {
         // bug we are trying to rule out.
         let build_dir = inputs
             .sketch
-            .join(".fbuild")
-            .join("build")
+            .join(fbuild_paths::FBUILD_DIR_NAME)
+            .join(fbuild_paths::BUILD_DIR_NAME)
             .join(&inputs.env_name)
             .join(match inputs.profile {
                 BuildProfile::Release => "release",

crates/fbuild-build/tests/eh_frame_strip_esp32.rs

@@ -52,7 +52,11 @@ async fn install_test_compile_backend() {
 }
 
 fn make_params(project_dir: &Path) -> BuildParams {
-    let build_dir = project_dir.join(".fbuild/build/esp32dev/release");
+    let build_dir = project_dir.join(format!(
+        "{}/{}/esp32dev/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     BuildParams {
         project_dir: project_dir.to_path_buf(),
         env_name: "esp32dev".to_string(),
@@ -141,7 +145,11 @@ async fn eh_frame_strip_drops_firmware_at_least_150kb() {
         .elf_path
         .clone()
         .expect("preserve build should produce ELF path");
-    let preserve_firmware_bin = preserve_dir.join(".fbuild/build/esp32dev/release/firmware.bin");
+    let preserve_firmware_bin = preserve_dir.join(format!(
+        "{}/{}/esp32dev/release/firmware.bin",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     std::env::remove_var("FBUILD_KEEP_EH_FRAME");
 
     // --- Build 2: strip eh_frame ---
@@ -156,7 +164,11 @@ async fn eh_frame_strip_drops_firmware_at_least_150kb() {
         .elf_path
         .clone()
         .expect("strip build should produce ELF path");
-    let strip_firmware_bin = strip_dir.join(".fbuild/build/esp32dev/release/firmware.bin");
+    let strip_firmware_bin = strip_dir.join(format!(
+        "{}/{}/esp32dev/release/firmware.bin",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     std::env::remove_var("FBUILD_STRIP_EH_FRAME");
 
     // --- firmware.bin delta ---

crates/fbuild-build/tests/esp32_build.rs

@@ -93,7 +93,11 @@ void loop() {
     )
     .unwrap();
 
-    let build_dir = project_dir.join(".fbuild/build/esp32dev/release");
+    let build_dir = project_dir.join(format!(
+        "{}/{}/esp32dev/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     let params = BuildParams {
         project_dir: project_dir.to_path_buf(),
         env_name: "esp32dev".to_string(),
@@ -187,7 +191,11 @@ void loop() {
     )
     .unwrap();
 
-    let build_dir = project_dir.join(".fbuild/build/esp32c6/release");
+    let build_dir = project_dir.join(format!(
+        "{}/{}/esp32c6/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     let params = BuildParams {
         project_dir: project_dir.to_path_buf(),
         env_name: "esp32c6".to_string(),
@@ -274,7 +282,11 @@ void loop() {
     )
     .unwrap();
 
-    let build_dir = project_dir.join(".fbuild/build/esp32c3/release");
+    let build_dir = project_dir.join(format!(
+        "{}/{}/esp32c3/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     let params = BuildParams {
         project_dir: project_dir.to_path_buf(),
         env_name: "esp32c3".to_string(),
@@ -362,7 +374,11 @@ void loop() {
     )
     .unwrap();
 
-    let build_dir = project_dir.join(".fbuild/build/esp32s3/release");
+    let build_dir = project_dir.join(format!(
+        "{}/{}/esp32s3/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     let params = BuildParams {
         project_dir: project_dir.to_path_buf(),
         env_name: "esp32s3".to_string(),
@@ -440,7 +456,11 @@ async fn build_esp32s3_fixture() {
     }
     install_test_compile_backend().await;
 
-    let build_dir = project_dir.join(".fbuild/build/esp32s3/release");
+    let build_dir = project_dir.join(format!(
+        "{}/{}/esp32s3/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     let params = BuildParams {
         project_dir: project_dir.clone(),
         env_name: "esp32s3".to_string(),
@@ -509,7 +529,11 @@ async fn build_nightdriverstrip_demo() {
     install_test_compile_backend().await;
 
     let tmp = tempfile::TempDir::new().unwrap();
-    let build_dir = tmp.path().join(".fbuild/build/demo/release");
+    let build_dir = tmp.path().join(format!(
+        "{}/{}/demo/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
 
     let params = BuildParams {
         project_dir: project_dir.clone(),
@@ -595,7 +619,11 @@ async fn incremental_nightdriverstrip_no_changes() {
 async fn incremental_build_at(project_dir: &std::path::Path, env_name: &str) {
     // Verify there's an existing build
     let build_marker = project_dir
-        .join(".fbuild/build")
+        .join(format!(
+            "{}/{}",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        ))
         .join(env_name)
         .join("release/firmware.elf");
     if !build_marker.exists() {
@@ -683,7 +711,11 @@ async fn incremental_nightdriverstrip_one_file_changed() {
 
     let env_name = "demo";
     let build_marker = project_dir
-        .join(".fbuild/build")
+        .join(format!(
+            "{}/{}",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        ))
         .join(env_name)
         .join("release/firmware.elf");
     if !build_marker.exists() {

crates/fbuild-build/tests/nxplpc_build_flags.rs

@@ -83,7 +83,11 @@ async fn lpc845brk_propagates_build_flags_to_library_compile_587() {
 
     // Build into a temp dir so reruns are clean and don't litter the repo.
     let tmp = tempfile::TempDir::new().expect("tempdir");
-    let build_dir = tmp.path().join(".fbuild/build/lpc845brk/release");
+    let build_dir = tmp.path().join(format!(
+        "{}/{}/lpc845brk/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
 
     let params = BuildParams {
         project_dir: fixture.clone(),

crates/fbuild-build/tests/nxplpc_core_compile_commands.rs

@@ -52,7 +52,11 @@ async fn build_core_repo(repo: &Path, env_name: &str) -> tempfile::TempDir {
     let tmp = tempfile::TempDir::new().expect("tempdir");
     let build_dir = tmp
         .path()
-        .join(".fbuild/build")
+        .join(format!(
+            "{}/{}",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        ))
         .join(env_name)
         .join("release");
 
@@ -96,9 +100,11 @@ async fn arduino_core_lpc845brk_compile_commands_match_platform_txt() {
         return;
     };
     let tmp = build_core_repo(&repo, "lpc845brk").await;
-    let compile_db = tmp
-        .path()
-        .join(".fbuild/build/lpc845brk/release/compile_commands.json");
+    let compile_db = tmp.path().join(format!(
+        "{}/{}/lpc845brk/release/compile_commands.json",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     let text = fs::read_to_string(&compile_db).expect("compile_commands.json");
     let entries: Vec<Value> = serde_json::from_str(&text).expect("valid compile database");
     let args = entries

crates/fbuild-build/tests/stm32_acceptance.rs

@@ -82,7 +82,11 @@ async fn stm32f103c8_blink_with_spi_auto_discovers_library_205_ac4() {
     )
     .unwrap();
 
-    let build_dir = project_dir.join(".fbuild/build/stm32f103c8/release");
+    let build_dir = project_dir.join(format!(
+        "{}/{}/stm32f103c8/release",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     let params = BuildParams {
         project_dir: project_dir.to_path_buf(),
         env_name: "stm32f103c8".to_string(),