Merge pull request #17 from MrVampy/fix/save-hook-path-augment

fix: augment hook PATH so python3 is reachable from restricted tmux servers

Author: timvw

README.md

@@ -318,6 +318,7 @@ cat ~/.tmux/resurrect/assistant-save.log
 | Save finds 0 sessions | Run `ps -eo pid=,ppid=,args= \| grep -E 'claude\|opencode\|codex'` to verify assistants are running |
 | Session ID missing for Claude | Verify the hook is installed: `jq '.hooks.SessionStart' ~/.claude/settings.json` |
 | Session ID missing for OpenCode | Launch with `-s <id>`, or verify the plugin: `ls ~/.config/opencode/plugins/session-tracker.js` |
+| Codex/OpenCode session ID missing (python3 methods) | The save hook auto-detects `python3` in common locations. If your setup uses a non-standard path, set it in tmux: `set-environment -g PATH "/your/python3/dir:$PATH"` |
 | Restore launches but assistant says "session not found" | The session ID may have expired. This is normal — start a fresh session and the next save will pick up the new ID |
 | Assistants launch twice after restore | Make sure assistants are **not** listed in `@resurrect-processes` — the plugin handles all resuming via the post-restore hook |
 | `just test` fails with Docker errors | Ensure Docker is running and you have network access (the image pulls npm packages) |
@@ -371,6 +372,30 @@ State files live in a user-only directory (mode 0700).
 > sidecar JSON persist to disk and may outlive the process they were captured
 > from.
 
+### PATH in restricted environments (NixOS, systemd services)
+
+When tmux runs as a systemd user service, the server inherits a stripped-down
+`PATH` that may not include `python3`. The save hook automatically checks common
+system locations (`/run/current-system/sw/bin`, `/opt/homebrew/bin`,
+`/usr/local/bin`, `/usr/bin`) and augments `PATH` if needed. This is a no-op
+when `python3` is already on `PATH`.
+
+If your `python3` is in a non-standard location, the recommended fix is at the
+tmux level:
+
+```bash
+# In tmux.conf — ensures all hooks and plugins see the right PATH:
+set-environment -g PATH "/your/custom/bin:/usr/local/bin:/usr/bin:/bin"
+```
+
+Or fix it in the systemd unit:
+
+```ini
+# ~/.config/systemd/user/tmux.service.d/override.conf
+[Service]
+Environment=PATH=/run/current-system/sw/bin:/usr/local/bin:/usr/bin:/bin
+```
+
 ### Continuum save interval
 
 Edit `config/resurrect-assistants.conf`:

scripts/save-assistant-sessions.sh

@@ -1,4 +1,21 @@
 #!/usr/bin/env bash
+# The tmux server may have been started with a limited PATH (e.g. via a
+# systemd user service with a whitelisted runtime environment). That PATH
+# is inherited by every hook this script runs in, so utilities like
+# python3 — needed by Methods 3 and 4 of get_codex_session — can be
+# missing even though they are installed and work fine from an
+# interactive shell. Augment PATH with common system locations so the
+# hook context sees what the rest of the system sees.
+if ! command -v python3 >/dev/null 2>&1; then
+	for _dir in /run/current-system/sw/bin /opt/homebrew/bin /usr/local/bin /usr/bin; do
+		if [ -x "$_dir/python3" ]; then
+			PATH="$_dir:$PATH"
+			break
+		fi
+	done
+	unset _dir
+fi
+
 # tmux-resurrect save hook — collects assistant session IDs from all tmux panes.
 # Writes a sidecar JSON file alongside resurrect's save files.
 #

test/run-tests.sh

@@ -1056,6 +1056,54 @@ fi
 HOME="$ORIG_HOME"
 rm -rf "$ROLLOUT_TEST_DIR"
 
+# --- Codex rollout: restricted PATH (regression for PATH augmentation) ---
+# When the tmux server inherits a stripped PATH (e.g. systemd user service),
+# python3 may not be found. The save script augments PATH at startup so that
+# python3-based methods (Codex rollout, OpenCode DB) still work.
+
+echo ""
+echo "=== PATH augmentation: Codex rollout works under restricted PATH ==="
+echo ""
+
+PATH_TEST_DIR=$(mktemp -d)
+mkdir -p "$PATH_TEST_DIR/.codex/sessions/2026/04/23"
+cat >"$PATH_TEST_DIR/.codex/sessions/2026/04/23/rollout-path-test.jsonl" <<'PATHROLLOUT'
+{"timestamp":"2026-04-23T10:00:00.000Z","type":"session_meta","payload":{"id":"ses_path_repro","timestamp":"2026-04-23T10:00:00.000Z","cwd":"/tmp/path-repro","originator":"codex_cli_rs","cli_version":"0.116.0"}}
+PATHROLLOUT
+
+# Build a minimal PATH that has the coreutils the script needs but NOT python3
+rbin=$(mktemp -d)
+for _c in dirname mkdir sed ps tr tail mv cat date jq awk gzip tar md5sum; do
+	_p=$(command -v "$_c" 2>/dev/null || true)
+	[ -n "$_p" ] && ln -sf "$_p" "$rbin/$_c"
+done
+# Also need bash itself for the subshell
+ln -sf "$(command -v bash)" "$rbin/bash"
+
+# Run the save script's preamble + get_codex_session under the restricted PATH.
+# The PATH augmentation block should find python3 and make Method 3 work.
+ORIG_HOME_PATH="$HOME"
+HOME="$PATH_TEST_DIR"
+path_aug_sid=$(PATH="$rbin" ${TEST_BASH:-bash} -c '
+	source "'"$REPO_DIR"'/scripts/save-assistant-sessions.sh"
+	get_codex_session $$ "codex" "/tmp/path-repro"
+')
+HOME="$ORIG_HOME_PATH"
+
+assert_eq "Codex rollout lookup works with restricted hook PATH" "ses_path_repro" "$path_aug_sid"
+
+# Verify that when python3 IS already on PATH, the augmentation is a no-op
+path_before="$PATH"
+# Re-source the script (it guards with command -v python3)
+source "$REPO_DIR/scripts/save-assistant-sessions.sh"
+if [ "$PATH" = "$path_before" ]; then
+	pass "PATH unchanged when python3 already available"
+else
+	fail "PATH was modified even though python3 was already on PATH"
+fi
+
+rm -rf "$PATH_TEST_DIR" "$rbin"
+
 # --- OpenCode: -s and --session arg extraction ---
 assert_eq "OpenCode -s extraction" "ses_oc_456" "$(get_opencode_session 99999 "opencode -s ses_oc_456" "/tmp")"
 assert_eq "OpenCode --session extraction" "ses_oc_789" "$(get_opencode_session 99999 "opencode --session ses_oc_789" "/tmp")"