full fix

Author: rickeylev

CHANGELOG.md

@@ -86,6 +86,9 @@ END_UNRELEASED_TEMPLATE
 
 {#v0-0-0-fixed}
 ### Fixed
+* (bootstrap) The stage1 bootstrap script now correctly handles nested `RUNFILES_DIR`
+  environments, fixing issues where a `py_binary` calls another `py_binary`
+  ([#3187](https://github.com/bazel-contrib/rules_python/issues/3187)).
 * (pypi) Fixes an issue where builds using a `bazel vendor` vendor directory
   would fail if the constraints file contained environment markers. Fixes
   [#2996](https://github.com/bazel-contrib/rules_python/issues/2996).

python/private/python_bootstrap_template.txt

@@ -516,7 +516,6 @@ def Main():
   if os.environ.get("RULES_PYTHON_TESTING_TELL_MODULE_SPACE"):
     new_env["RULES_PYTHON_TESTING_MODULE_SPACE"] = module_space
 
-  print(f"===== module space: {module_space}")
   python_imports = '%imports%'
   python_path_entries = CreatePythonPathEntries(python_imports, module_space)
   python_path_entries += GetRepositoriesImports(module_space, %import_all%)
@@ -539,7 +538,6 @@ def Main():
   new_env['PYTHONPATH'] = python_path
   runfiles_envkey, runfiles_envvalue = RunfilesEnvvar(module_space)
   if runfiles_envkey:
-    print(f"===== setting {runfiles_envkey} = {runfiles_envvalue}")
     new_env[runfiles_envkey] = runfiles_envvalue
 
   # Don't prepend a potentially unsafe path to sys.path

python/private/stage1_bootstrap_template.sh

@@ -70,6 +70,9 @@ else
       maybe_root="${RUNFILES_MANIFEST_FILE%%.runfiles/MANIFEST}.runfiles"
     fi
 
+    # The RUNFILES_DIR et al variables may misreport the runfiles directory
+    # if an outer binary invokes this binary when it isn't a data dependency.
+    # e.g. a genrule calls `bazel-bin/outer --inner=bazel-bin/inner`
     if [[ -n "$maybe_root" && -e "$maybe_root/$STAGE2_BOOTSTRAP" ]]; then
       echo "$maybe_root"
       return 0
@@ -102,6 +105,9 @@ else
   RUNFILES_DIR=$(find_runfiles_root $0)
 fi
 
+if [[ -n "$RULES_PYTHON_TESTING_TELL_MODULE_SPACE" ]]; then
+  export RULES_PYTHON_TESTING_MODULE_SPACE="$RUNFILES_DIR"
+fi
 
 function find_python_interpreter() {
   runfiles_root="$1"