fix(agent): use GIT_AUTHOR/COMMITTER env vars instead of git config --global (#622) (#623)

run_task() set the bot's git identity via `git config --global user.name/email`,
which writes to ~/.gitconfig for whatever OS user runs the process. In the
ephemeral ECS container that's intended, but the same code path runs on
developer workstations (local agent runs, dry-runs, pytest reaching run_task),
permanently clobbering the developer's real identity to `bgagent`.

Replace the two `git config --global` subprocess calls with process-scoped
GIT_AUTHOR_NAME/EMAIL and GIT_COMMITTER_NAME/EMAIL env vars, set alongside the
existing os.environ writes. Git honors these for every commit (inherited by
Claude Code and the safety-net commit in post_hooks) without touching any
on-disk config, so container commits stay attributed to bgagent while a
developer's ~/.gitconfig is never modified.

Removes the now-unused `subprocess` import. Adds a regression test asserting
the identity env vars are set. The GitHub PAT flow (GITHUB_TOKEN/GH_TOKEN from
the blueprint's Secrets Manager secret) is unchanged.

Co-authored-by: scottschreckengaust <345885+scottschreckengaust@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: scottschreckengaust

agent/src/pipeline.py

@@ -5,7 +5,6 @@
 import asyncio
 import hashlib
 import os
-import subprocess
 import sys
 import time
 from typing import TYPE_CHECKING
@@ -822,19 +821,17 @@ def _on_trace_truncated(max_bytes: int, first_dropped: int) -> None:
                     system_prompt_overrides=system_prompt_overrides,
                 )
 
-            # Configure git and gh auth before setup_repo() uses them
-            subprocess.run(
-                ["git", "config", "--global", "user.name", "bgagent"],
-                check=True,
-                capture_output=True,
-                timeout=60,
-            )
-            subprocess.run(
-                ["git", "config", "--global", "user.email", "bgagent@noreply.github.com"],
-                check=True,
-                capture_output=True,
-                timeout=60,
-            )
+            # Configure git identity and gh auth before setup_repo() uses them.
+            # Use GIT_AUTHOR_*/GIT_COMMITTER_* env vars rather than
+            # `git config --global`: git honors these for every commit (inherited
+            # by Claude Code and the safety-net commit in post_hooks) WITHOUT
+            # writing to any on-disk config. `--global` would clobber the real
+            # ~/.gitconfig — harmless in the ephemeral container, but destructive
+            # when this pipeline runs on a developer workstation (#622).
+            os.environ["GIT_AUTHOR_NAME"] = "bgagent"
+            os.environ["GIT_AUTHOR_EMAIL"] = "bgagent@noreply.github.com"
+            os.environ["GIT_COMMITTER_NAME"] = "bgagent"
+            os.environ["GIT_COMMITTER_EMAIL"] = "bgagent@noreply.github.com"
             os.environ["GITHUB_TOKEN"] = config.github_token
             os.environ["GH_TOKEN"] = config.github_token
 

agent/tests/test_pipeline.py

@@ -1,5 +1,6 @@
 """Unit tests for pipeline.py — cedar_policies injection and pure helpers."""
 
+import os
 from unittest.mock import MagicMock, patch
 
 import pytest
@@ -142,6 +143,78 @@ async def fake_run_agent(_prompt, _system_prompt, config, cwd=None, trajectory=N
         assert captured_config is not None
         assert captured_config.cedar_policies == []
 
+    @patch("runner.run_agent")
+    @patch("pipeline.build_system_prompt")
+    @patch("pipeline.discover_project_config")
+    @patch("repo.setup_repo")
+    @patch("pipeline.task_span")
+    @patch("pipeline.task_state")
+    def test_git_identity_uses_env_vars_not_global_config(
+        self,
+        _mock_task_state,
+        mock_task_span,
+        mock_setup_repo,
+        _mock_discover,
+        _mock_build_prompt,
+        mock_run_agent,
+        monkeypatch,
+    ):
+        """Git identity is set via GIT_AUTHOR/COMMITTER env vars, never
+        `git config --global`, so a developer's ~/.gitconfig is never
+        clobbered when the pipeline runs on a workstation (#622)."""
+        monkeypatch.setenv("GITHUB_TOKEN", "ghp_test")
+        monkeypatch.setenv("AWS_REGION", "us-east-1")
+        # Ensure a clean slate so the assertion proves the pipeline set them.
+        for var in (
+            "GIT_AUTHOR_NAME",
+            "GIT_AUTHOR_EMAIL",
+            "GIT_COMMITTER_NAME",
+            "GIT_COMMITTER_EMAIL",
+        ):
+            monkeypatch.delenv(var, raising=False)
+
+        mock_setup_repo.return_value = RepoSetup(
+            repo_dir="/workspace/repo",
+            branch="bgagent/test/branch",
+            build_before=True,
+        )
+
+        async def fake_run_agent(_prompt, _system_prompt, config, cwd=None, trajectory=None):
+            return AgentResult(status="success", turns=1, cost_usd=0.01, num_turns=1)
+
+        mock_run_agent.side_effect = fake_run_agent
+
+        mock_span = MagicMock()
+        mock_span.__enter__ = MagicMock(return_value=mock_span)
+        mock_span.__exit__ = MagicMock(return_value=False)
+        mock_task_span.return_value = mock_span
+
+        with (
+            patch("pipeline.ensure_committed", return_value=False),
+            patch("pipeline.verify_build", return_value=True),
+            patch("pipeline.verify_lint", return_value=True),
+            patch(
+                "pipeline.ensure_pr",
+                return_value="https://github.com/org/repo/pull/1",
+            ),
+            patch("pipeline.get_disk_usage", return_value=0),
+            patch("pipeline.print_metrics"),
+        ):
+            from pipeline import run_task
+
+            run_task(
+                repo_url="owner/repo",
+                task_description="fix bug",
+                github_token="ghp_test",
+                aws_region="us-east-1",
+                task_id="test-id",
+            )
+
+        assert os.environ["GIT_AUTHOR_NAME"] == "bgagent"
+        assert os.environ["GIT_AUTHOR_EMAIL"] == "bgagent@noreply.github.com"
+        assert os.environ["GIT_COMMITTER_NAME"] == "bgagent"
+        assert os.environ["GIT_COMMITTER_EMAIL"] == "bgagent@noreply.github.com"
+
 
 class TestRepoLessPipeline:
     """#248 Phase 3: a repo-less workflow runs the agent with no clone/build/PR."""