From db42934270c5c23be9f6804cad98dfd8234caf6f Mon Sep 17 00:00:00 2001
From: Seth Michael Larson <seth@python.org>
Date: Mon, 2 Sep 2024 14:35:30 -0500
Subject: [PATCH] gh-123458: Skip SBOM generation if no git repository is
 detected (#123507)

---
 Tools/build/generate_sbom.py | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Tools/build/generate_sbom.py b/Tools/build/generate_sbom.py
index 88f311bf6b4..020f874cffe 100644
--- a/Tools/build/generate_sbom.py
+++ b/Tools/build/generate_sbom.py
@@ -93,6 +93,19 @@ def error_if(value: bool, error_message: str) -> None:
         sys.exit(1)
 
 
+def is_root_directory_git_index() -> bool:
+    """Checks if the root directory is a git index"""
+    try:
+        subprocess.check_call(
+            ["git", "-C", str(CPYTHON_ROOT_DIR), "rev-parse"],
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
+        )
+    except subprocess.CalledProcessError:
+        return False
+    return True
+
+
 def filter_gitignored_paths(paths: list[str]) -> list[str]:
     """
     Filter out paths excluded by the gitignore file.
@@ -338,6 +351,11 @@ def create_externals_sbom() -> None:
 
 
 def main() -> None:
+    # Don't regenerate the SBOM if we're not a git repository.
+    if not is_root_directory_git_index():
+        print("Skipping SBOM generation due to not being a git repository")
+        return
+
     create_source_sbom()
     create_externals_sbom()