Include nested gitignores with pants_ignore to ignore for file watching

pants.toml

@@ -48,22 +48,11 @@ plugins = [
 pantsd_invalidation_globs.add = [
   "!*_test.py",
   "!BUILD",
-  # NB: The `target` directory is ignored via `pants_ignore` below.
   "src/rust/engine/**/*.rs",
   "src/rust/engine/**/*.toml",
 ]
-# Path patterns to ignore for filesystem operations on top of the builtin patterns.
 pants_ignore.add = [
-  # venv directories under build-support.
-  "/build-support/*.venv/",
-  # We shouldn't walk or watch the rust compiler artifacts because it is slow.
-  "/src/rust/engine/target",
-  # We want to .gitignore Java .class files, but pants should pay attention to them.
-  "!*.class",
-  # We also want to override the .gitignore'd pants.pex file
-  "!/pants.pex",
-  # Ignore node modules for docs processing tools
-  "/docs/node_modules",
+  "!src/python/pants/engine/internals/native_engine.so*",
 ]
 
 build_ignore.add = [

src/python/pants/option/global_options.py

@@ -920,8 +920,6 @@ class BootstrapOptions:
             Patterns from `[GLOBAL].pants_ignore` take precedence over these files' rules. For
             example, you can use `!my_pattern` in `pants_ignore` to have Pants operate on files
             that are gitignored.
-
-            Warning: this does not yet support reading nested gitignore files.
             """
         ),
     )

src/rust/engine/fs/Cargo.toml

@@ -27,6 +27,7 @@ rlimit = "0.8"
 serde = "1.0.136"
 task_executor = { path = "../task_executor" }
 tokio = { version = "1.21", features = ["fs"] }
+walkdir = "2"
 workunit_store = { path = "../workunit_store" }
 
 [dev-dependencies]