Fix CrossHair subprocess missing PYTHONPATH

[KRRT7]

Summary

• Prepend project_root to PYTHONPATH before spawning the CrossHair subprocess in concolic_testing.py, matching the pattern used by every other subprocess (tracer, test runner, benchmarks).
• Fixes ModuleNotFoundError for project-relative imports (e.g. Django projects) during concolic test generation.

Test plan

• Existing concolic tests pass (88/88)
• Verify CrossHair resolves project-relative imports in a Django-style project

[claude]

PR Review Summary

Prek Checks

All checks passed. No formatting or linting issues found.

Mypy

No new type errors introduced. Two pre-existing mypy errors exist in this file (var-annotated on line 47 and no-redef on line 109), but they are not related to this PR's changes.

Code Review

No critical issues found. This is a clean, focused fix:

• Adds PYTHONPATH propagation to the CrossHair subprocess call in concolic_testing.py, matching the established pattern used in tracer.py (lines 134-158, 177-200)
• The pattern (os.environ.copy() → check/prepend project_root → pass env=env) is consistent with how all other subprocess calls handle PYTHONPATH in this codebase
• No security concerns — environment is copied (not shared), and only project_root is prepended
• No breaking API changes

Test Coverage

File	Stmts	Covered	Coverage
codeflash/verification/concolic_testing.py	61	18	30%

Analysis:

• The new lines (67-73, 97) are not directly covered by unit tests, but the entire generate_concolic_tests function body (lines 46-132) was already uncovered before this PR
• Coverage is unchanged — only module-level imports and the function signature are exercised by the test suite
• This function requires CrossHair and subprocess integration to test, which is validated by the existing 88/88 concolic test suite mentioned in the PR description
• No coverage regression from this change

Optimization PRs

Checked 7 open codeflash-ai[bot] PRs targeting main. None are eligible for merge — all have CI failures (pre-commit hooks, type-check, or unit test failures).

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Last updated: 2026-02-13T03:40Z