fix(docker): preserve custom PATH entries in subprocess environment (#70905)

[webtecnica]

Fix: Preserve custom PATH entries in agent's subprocess execution context

Closes #70905

Problem

Custom PATH entries set via Dockerfile ENV, .env files, or config.yaml (terminal.env / docker_env) are silently dropped, causing command not found (exit 127) when the agent runs installed binaries.

Root cause

Two issues combined:

1. _make_run_env (local.py): The filtering loop that strips Hermes provider credentials from the subprocess env had no fallback chain for PATH. If a future expansion of the blocklist accidentally filtered PATH, or the run_env PATH was empty, the custom entries would be lost.

2. DockerEnvironment._build_init_env_args (docker.py): The -e env-var flags passed to docker exec during init_session only included docker_env overrides and forwarded/passthrough vars. PATH from the container's default environment (Dockerfile ENV) was NOT explicitly forwarded. When the login shell's profile scripts (/etc/profile, ~/.bashrc) truncated or reset PATH, the init_session snapshot would capture a narrower PATH than the container's default, silently losing custom entries on every subsequent execute() call.

Fix

1. _make_run_env: Add a PATH propagation guard that restores PATH from os.environ if the filtering loop drops it, and falls back to os.environ when the run_env PATH is empty.

2. _build_init_env_args: Explicitly include PATH from the host os.environ when it's not already overridden by docker_env, so the init_session snapshot always captures the full PATH.

3. New test suite (tests/tools/test_path_propagation.py): 12 tests covering custom PATH preservation, _SANE_PATH fallback, terminal.env override, multiple custom entries, empty PATH recovery, and full execute() integration.

Testing

• pytest tests/tools/test_path_propagation.py — 12/12 passed
• pytest tests/tools/test_local_env_blocklist.py — all existing tests pass
• pytest tests/tools/test_env_passthrough.py — all existing tests pass
• pytest tests/tools/test_hermes_subprocess_env.py — all existing tests pass

[isak-ialogics]

The current branch includes two unrelated commits before the PATH fix: 9a8a3d3 (the cron 401/403 change from #70913) and 8af2053 (the execution-ledger change from #70917). That is why this nominal PATH PR also modifies cron/executions.py, cron/scheduler.py, and cron tests, and the attribution/required-check gate is failing. Suggested next action: rebase onto current main (or recreate the branch) with only 6338165 and the PATH-related files, then rerun CI.

[teknium1]

Thanks for investigating the PATH-loss report. The Docker snapshot path is the right area to examine, but the current implementation does not preserve the container-defined value.

Problems

• In this diff, tools/environments/docker.py:1518 reads os.environ["PATH"] from the Docker host. Main injects those arguments into docker exec at tools/environments/docker.py:1511-1523, while the container image defines its own runtime PATH at Dockerfile:415. The host PATH cannot carry a container-only Dockerfile entry such as /potato.
• tests/tools/test_path_propagation.py:15-22 exercises only LocalEnvironment; it has no Docker backend or derived-image reproduction. This does not validate the reported snapshot failure.
• As noted in the existing PR discussion, the reviewed diff still contains unrelated cron changes in cron/executions.py and cron/scheduler.py.

Suggested changes

• Preserve the target container's pre-login PATH, then apply an explicit docker_env PATH override with defined precedence rather than forwarding the host PATH.
• Add a Docker integration regression with a derived image whose ENV PATH includes /potato and verify its binary through the session snapshot path.

This is an automated hermes-sweeper review.

[teknium1]

os.environ here belongs to the Docker host, not the target container. The reported /potato entry is introduced by the target image's Dockerfile, so forwarding this value cannot preserve that container-only PATH and may replace it during the login-shell snapshot. Capture the container's pre-login PATH instead, then apply any explicit docker_env override.

[GottZ]

This was generated by AI during triage.

Graph note (no action implied — a maintainer has already reviewed this thread).

Our triage graph places this PR in a complex with 1 related issue (#70905). They were checked against each other at the diff level and no consolidation is indicated — they address distinct causes.

Full neighbourhood: https://hermes-triage.gottz.de/?node=70923

This note exists so the relationship stays discoverable from the thread itself.