# Incomplete Handoff: Fix Failing `cargo test --lib`

## Status

Diagnosed and fixed the three failing unit tests in `src/session.rs`. They were failing because the `CRUISE_SDK` environment variable (set to `pi` in the runner) caused `WorkflowConfig::apply_env_overrides` to clear the `command` vector. The three affected tests now pass. The full `cargo test --lib` run was interrupted before completion due to tool-iteration limits.

## Done (this session)

- Confirmed the three failures by running `cargo test --lib`:
  - `session::tests::test_session_load_config_reads_valid_yaml`
  - `session::tests::test_session_load_config_reads_from_config_path_when_set`
  - `session::tests::test_session_load_config_falls_back_to_session_dir_when_config_path_none`
- Traced the root cause to `WorkflowConfig::apply_env_overrides` in `src/config.rs`, which sets `command` to `vec![]` when `CRUISE_SDK` is present.
- Added a test-only `EnvVarGuard` helper in `src/session.rs` that saves an env var, removes it for the duration of a test, and restores it on drop.
- Applied the guard to the three affected tests to isolate them from `CRUISE_SDK`.
- Verified the targeted session tests pass: `cargo test --lib session::tests::test_session_load_config` reports 5 passed, 0 failed.
- Committed the work:
  - commit: `405f405263cbb6d5cb48b7e621a95abbf3a3e331`
  - message: `fix: isolate session load_config tests from CRUISE_SDK env var`
  - files changed: `src/session.rs` (+35 lines)

## Remaining

1. **Run the full `cargo test --lib` suite** to confirm no other tests regress under the current environment. The previous run showed 798 passed / 3 failed before the fix; the targeted run now passes, but the full suite needs to be re-run end-to-end.
2. **Address any additional env-sensitive failures** if the full suite still fails. If other tests fail because of `CRUISE_SDK`, `CRUISE_MODEL`, `CRUISE_PLAN_MODEL`, `CRUISE_INTERACTIVE_PLANNING`, etc., extend `EnvVarGuard` to those tests/env vars.
3. **Run lint / format checks** (`cargo fmt --check`, `cargo clippy --all-targets`) to ensure the change meets CI standards.
4. **Verify the fix is minimal and correct** — the guard is intentionally scoped to tests only and does not alter production behavior.

## Next-Agent Starting Position

- Branch: current checked-out branch
- Commit: `405f405263cbb6d5cb48b7e621a95abbf3a3e331`
- Start by running `cargo test --lib` to see the full suite result.
- If the suite is green, proceed with `cargo clippy --all-targets` and `cargo fmt --check`.
- If additional env-sensitive tests fail, apply the same `EnvVarGuard` pattern (or expand it to multiple env vars) rather than changing production `apply_env_overrides` logic.
- The guard is located in `src/session.rs` inside the `#[cfg(test)] mod tests` block, right after the imports.
