fix: skip sentinel matches inside extra fixed dirs

CHANGELOG.md

@@ -17,6 +17,10 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+- Sentinel matches nested under directories configured with `[fixed_dirs] extra` are now
+  skipped, avoiding redundant per-directory Time Machine exclusions before the configured
+  parent directory is excluded ([#132](https://github.com/AsimovMac/asimov/issues/132)).
+
 ### Removed
 
 ## [0.12.0] — 2026-07-30

lib/asimov/exclude.sh

@@ -71,14 +71,24 @@ exclude_paths_from_stdin() {
     fi
     verbose_timing "Filtered: ${#to_exclude[@]} new, ${already_excluded} already excluded"
 
-    # Layer 2: Filter descendants of ASIMOV_FIXED_DIRS — they'll be excluded
-    # unconditionally later, so calling tmutil on them individually is wasted (~11s each).
-    if [[ "$ASIMOV_CONFIG_FIXED_DIRS_ENABLED" == "true" && ${#to_exclude[@]} -gt 0 ]]; then
+    # Layer 2: Filter descendants of enabled built-in fixed dirs and configured
+    # extra fixed dirs — they'll be excluded unconditionally later, so calling
+    # tmutil on them individually is wasted (~11s each).
+    local -a effective_fixed_dirs=()
+    if [[ "$ASIMOV_CONFIG_FIXED_DIRS_ENABLED" == "true" ]]; then
+        effective_fixed_dirs=("${ASIMOV_FIXED_DIRS[@]}")
+    fi
+    local configured_fixed_dir
+    for configured_fixed_dir in ${ASIMOV_CONFIG_EXTRA_FIXED_DIRS[@]+"${ASIMOV_CONFIG_EXTRA_FIXED_DIRS[@]}"}; do
+        effective_fixed_dirs+=("$configured_fixed_dir")
+    done
+
+    if [[ ${#effective_fixed_dirs[@]} -gt 0 && ${#to_exclude[@]} -gt 0 ]]; then
         local -a filtered_exclude=()
         for path in "${to_exclude[@]}"; do
             local under_fixed=false
             local fixed_dir
-            for fixed_dir in "${ASIMOV_FIXED_DIRS[@]}"; do
+            for fixed_dir in "${effective_fixed_dirs[@]}"; do
                 if [[ "$path" == "${fixed_dir}/"* ]]; then
                     under_fixed=true
                     break

tests/behavior.bats

@@ -370,6 +370,32 @@ extra = ~/.cache-b"
   assert_excluded "${HOME}/.cache-b"
 }
 
+@test "config: extra fixed dir suppresses nested sentinel exclusions when fixed dirs enabled" {
+  create_project ".custom-cache/My-Project" "package.json" "node_modules"
+  write_config "[fixed_dirs]
+enabled = true
+extra = ~/.custom-cache"
+
+  run_asimov --no-cache
+
+  assert_excluded "${HOME}/.custom-cache"
+  refute_excluded "${HOME}/.custom-cache/My-Project/node_modules"
+  [[ "$(count_exclusions)" -eq 1 ]]
+}
+
+@test "config: extra fixed dir suppresses nested sentinel exclusions when fixed dirs disabled" {
+  create_project ".custom-cache/My-Project" "package.json" "node_modules"
+  write_config "[fixed_dirs]
+enabled = false
+extra = ~/.custom-cache"
+
+  run_asimov --no-cache
+
+  assert_excluded "${HOME}/.custom-cache"
+  refute_excluded "${HOME}/.custom-cache/My-Project/node_modules"
+  [[ "$(count_exclusions)" -eq 1 ]]
+}
+
 @test "config: extra sentinel pair triggers exclusion" {
   create_project "Code/My-Project" "custom.config" ".custom-deps"
   write_config "[sentinels]