fix(windows): detect Git Bash/MSYS2/Cygwin from OSTYPE, as gstack-doctor does, so uname stubs in setup fixtures stay untouched

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

AGENTS.md

@@ -303,4 +303,4 @@ Agents poll `eval:bg:*` logs for the `### gstack-detach EXIT=<code> ###` sentine
 - Every Codex run's verdict goes through `lib/outside-review-result.ts`; its reason codes live in `lib/gate-outcomes.ts`, each with a `docs/troubleshooting.md` anchor.
 - `test/module-size-ratchet.test.ts` keeps refactored owner modules at or under 800 lines (150 per function) and residual files from growing.
 - The `claude` CLI binary resolves via `lib/claude-bin.ts` (re-exported from `browse/src/claude-bin.ts` for browse internals; `Bun.which()` + `GSTACK_CLAUDE_BIN` override). Set `GSTACK_CLAUDE_BIN=wsl` plus `GSTACK_CLAUDE_BIN_ARGS='["claude"]'` to run Claude through WSL on Windows.
-- Every Bun gstack starts ignores the working directory's `.env` files and `bunfig.toml`: bun shebangs are `#!/usr/bin/env -S bun --no-env-file --config=/dev/null`, skill prose passes `bun --no-env-file --config=/dev/null`, shipped shell files define `GSTACK_BUN_CONFIG` with the line in `test/bun-entry-isolation.test.ts` (`NUL` under MINGW, MSYS and Cygwin, where native Bun cannot open `/dev/null`, #3415) and pass `bun --no-env-file --config="${GSTACK_BUN_CONFIG:-/dev/null}"`, TypeScript spawns use `bunIsolationArgs()` from `lib/bun-isolation.ts`, and `bun build --compile` adds `--no-compile-autoload-dotenv --no-compile-autoload-bunfig`. `test/bun-entry-isolation.test.ts` enforces all four.
+- Every Bun gstack starts ignores the working directory's `.env` files and `bunfig.toml`: bun shebangs are `#!/usr/bin/env -S bun --no-env-file --config=/dev/null`, skill prose passes `bun --no-env-file --config=/dev/null`, shipped shell files define `GSTACK_BUN_CONFIG` with the line in `test/bun-entry-isolation.test.ts` (`NUL` when `OSTYPE` is `msys` or `cygwin`, where native Bun cannot open `/dev/null`, #3415) and pass `bun --no-env-file --config="${GSTACK_BUN_CONFIG:-/dev/null}"`, TypeScript spawns use `bunIsolationArgs()` from `lib/bun-isolation.ts`, and `bun build --compile` adds `--no-compile-autoload-dotenv --no-compile-autoload-bunfig`. `test/bun-entry-isolation.test.ts` enforces all four.

CHANGELOG.md

@@ -5,12 +5,12 @@
 **Windows: gstack's shell bins stop losing review, question, learning and timeline records when Git Bash path conversion is off (#3415).** Since GSTA-56 every shell bin started Bun with `--config=/dev/null`. Native `bun.exe` cannot open `/dev/null`: it exits 1 with `EINVAL` on Bun 1.3.10, 1.4.2 and 1.4.4 (measured on windows-latest). Git Bash hides this by rewriting the argument to `nul`, but only while MSYS path conversion is on. With it off (`MSYS_NO_PATHCONV` set to any value, even empty; `MSYS2_ARG_CONV_EXCL=*`; or Cygwin), `gstack-review-log`, `gstack-question-log` and `gstack-learnings-log` exited 1 with nothing written, and `gstack-timeline-log` exited 0 with nothing written.
 
 ### Fixed
-- **40 shipped shell files** (the bash bins, the Claude hook wrappers, `setup`, `scripts/build-cso.sh` and one migration) define `GSTACK_BUN_CONFIG` once (`NUL` under MINGW, MSYS and Cygwin, `/dev/null` elsewhere) and start Bun with `--config="${GSTACK_BUN_CONFIG:-/dev/null}"`. Bun 1.4.2 and later, gstack's minimum, read `NUL` as an empty config whether or not conversion is on. The `:-/dev/null` default fails closed: a call that loses its definition still passes `/dev/null`, so POSIX is unchanged and Windows fails loudly as before, and never reads the repository's `bunfig.toml`. `bin/gstack-codex-probe` is sourced into the caller's shell, so it defines the variable inside the one function that starts Bun and still runs nothing at source time.
+- **40 shipped shell files** (the bash bins, the Claude hook wrappers, `setup`, `scripts/build-cso.sh` and one migration) define `GSTACK_BUN_CONFIG` once (`NUL` when `OSTYPE` is `msys` or `cygwin`, as in Git Bash, MSYS2 and Cygwin, the check `gstack-doctor` already uses; `/dev/null` elsewhere) and start Bun with `--config="${GSTACK_BUN_CONFIG:-/dev/null}"`. Bun 1.4.2 and later, gstack's minimum, read `NUL` as an empty config whether or not conversion is on. The `:-/dev/null` default fails closed: a call that loses its definition still passes `/dev/null`, so POSIX is unchanged and Windows fails loudly as before, and never reads the repository's `bunfig.toml`. `bin/gstack-codex-probe` is sourced into the caller's shell, so it defines the variable inside the one function that starts Bun and still runs nothing at source time.
 - **`bin/gstack-timeline-log`**: invalid input still exits 0 with nothing logged (the hook-path contract). Its validator now exits 3 for invalid input, and any other non-zero exit, which is Bun itself failing, is reported on stderr and returned instead of being skipped as invalid.
 - Unchanged: bun shebangs and skill prose keep `--config=/dev/null`. A shebang cannot name a per-platform path, and with conversion off their POSIX script paths (`/c/Users/...`) fail in `bun.exe` anyway, so they work wherever they worked before. TypeScript spawns keep `bunIsolationArgs()`, and `scripts/ubicloud/` keeps `/dev/null` because it runs on Linux.
 
 ### Tests
-- `test/bun-config-shell-bins.test.ts` (new; force-included in the Windows lane): on every platform, the four record bins run through `lib/script-invocation.ts` with conversion off in a repository whose `bunfig.toml` preload and `.env` are hostile. Each writes exactly one record, and neither the preload nor the `.env` state root takes effect. Invalid timeline input still exits 0 silently. On POSIX hosts a simulated Windows bash (uname reports MINGW64, and a `bun` stand-in rejects `/dev/null` with EINVAL as `bun.exe` does) reproduces the bug: on main the four bins write nothing and the timeline control exits 0 (5 failures); with the fix they pass. The controls, with uname reporting Linux, show each bin exits non-zero with nothing written.
+- `test/bun-config-shell-bins.test.ts` (new; force-included in the Windows lane): on every platform, the four record bins run through `lib/script-invocation.ts` with conversion off in a repository whose `bunfig.toml` preload and `.env` are hostile. Each writes exactly one record, and neither the preload nor the `.env` state root takes effect. Invalid timeline input still exits 0 silently. On POSIX hosts a simulated Windows bash (`OSTYPE=msys`, and a `bun` stand-in rejects `/dev/null` with EINVAL as `bun.exe` does) reproduces the bug: on main the four bins write nothing and the timeline control exits 0 (5 failures); with the fix they pass. The controls, without `OSTYPE=msys`, show each bin exits non-zero with nothing written.
 - `test/bun-isolation-launch.test.ts`: the shell-file spelling stays isolated with conversion off, and a win32-only control shows that the literal `--config=/dev/null` fails there with EINVAL.
 - `test/bun-entry-isolation.test.ts`: shipped shell files must use the fail-closed spelling and define `GSTACK_BUN_CONFIG` with the canonical line before first use. Skill sources keep the literal spelling.
 - `test/learnings-injection.test.ts`, `browse/test/learnings-injection.test.ts` and `test/setup-hook-canonical-paths.test.ts` now anchor on the new spelling. Their assertions are unchanged.

autoplan/bin/phase-publication-hook

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 # Native Read barrier. A broken install must return deny JSON, never silence.
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 _AUTOPLAN_DECIDED=''
 _autoplan_backstop() {
   if [ -z "$_AUTOPLAN_DECIDED" ]; then

bin/gstack-brain-sync

@@ -77,7 +77,7 @@
 BASH_COMPAT=50
 
 set -uo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 . "$(dirname "$0")/gstack-state-root.sh" 2>/dev/null || { echo "$0: cannot resolve the gstack state root: $(dirname "$0")/gstack-state-root.sh is missing. fix: reinstall with ./setup or /gstack-upgrade (docs/state-root.md)" >&2; exit 1; }
 gstack_state_root_select

bin/gstack-browser-ensure

@@ -24,7 +24,7 @@
 # GSTACK_CHROMIUM_NO_SANDBOX=1 for the probe. Bash 3.2 plus POSIX tools.
 BASH_COMPAT=50
 set -u
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)" || { echo "gstack-browser-ensure: cannot resolve the install root" >&2; exit 1; }
 DOCS="https://github.com/garrytan/gstack/blob/main/docs/troubleshooting.md#browser-ensure-failed"

bin/gstack-codex-probe

@@ -157,7 +157,7 @@ _gstack_codex_select_model() {
   # working-directory context forwarded to the shared role resolver.
   # The TOML is read by the TypeScript resolver; bash never parses it.
   local _kind="${1:-exec}" _explicit="${2:-}" _role="${3:-}" _cwd="${4:-}" _line _rc _rest
-  local GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+  local GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
   case "$_kind" in exec|review) ;; *) echo "ERROR: _gstack_codex_select_model takes exec or review" >&2; return 2 ;; esac
   case "$_role" in ''|plan-review) ;; *) echo "ERROR: _gstack_codex_select_model role must be plan-review" >&2; return 2 ;; esac
   if ! command -v bun >/dev/null 2>&1; then

bin/gstack-codex-session-import

@@ -20,7 +20,7 @@
 # Writes via bin/gstack-question-log so source tagging, dedup, and async
 # derive all apply uniformly.
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 . "$(dirname "$0")/gstack-state-root.sh" 2>/dev/null || { echo "$0: cannot resolve the gstack state root: $(dirname "$0")/gstack-state-root.sh is missing. fix: reinstall with ./setup or /gstack-upgrade (docs/state-root.md)" >&2; exit 1; }
 gstack_state_root_select

bin/gstack-developer-profile

@@ -28,7 +28,7 @@
 # docs/designs/PLAN_TUNING_V0.md). Event file: ~/.gstack/projects/{SLUG}/
 # question-events.jsonl.
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 ROOT_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"

bin/gstack-distill-apply

@@ -23,7 +23,7 @@
 #   gstack-distill-apply --proposal <N> --gbrain-published true
 #   gstack-distill-apply --list                        # show pending proposals
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 . "$(dirname "$0")/gstack-state-root.sh" 2>/dev/null || { echo "$0: cannot resolve the gstack state root: $(dirname "$0")/gstack-state-root.sh is missing. fix: reinstall with ./setup or /gstack-upgrade (docs/state-root.md)" >&2; exit 1; }
 gstack_state_root_select

bin/gstack-distill-free-text

@@ -20,7 +20,7 @@
 # auditability via --status when you want it.
 # Per D6: Anthropic SDK direct call, fail-loud on missing ANTHROPIC_API_KEY.
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 # Heredoc delivery guard. bash 5.2+ writes a heredoc body <=64KiB through a
 # pipe in the forked child before exec, with no reader on the other end. On

bin/gstack-doctor

@@ -40,7 +40,7 @@
 BASH_COMPAT=50
 
 set -u
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 usage() {
   sed -n '3,13p' "$0" | sed 's/^# \{0,1\}//'

bin/gstack-doctor-check.sh

@@ -19,7 +19,7 @@
 # remote's capy/support.env, `unknown` when its fetch failed, or ""), LIVE.
 # GSTACK_CAPY_WRAPPER_PATH (optional) names the wrapper a below-minimum fix runs.
 
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 . "$BIN/gstack-doctor-components.sh" || { echo "gstack-doctor: $BIN/gstack-doctor-components.sh is missing; reinstall with cd $SRC && ./setup" >&2; exit 1; }
 . "$BIN/gstack-install-registry.sh" 2>/dev/null || { echo "gstack-doctor: $BIN/gstack-install-registry.sh is missing; reinstall with cd $SRC && ./setup" >&2; exit 1; }
 . "$BIN/gstack-bun-version.sh" 2>/dev/null || { echo "gstack-doctor: $BIN/gstack-bun-version.sh is missing; reinstall with cd $SRC && ./setup" >&2; exit 1; }

bin/gstack-gbrain-install

@@ -36,7 +36,7 @@
 #   2 — prerequisite missing or invalid argument
 #   3 — post-install validation failed (PATH shadow, broken binary, etc.)
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 # --- defaults ---
 # No version pin by default — install the latest default-branch HEAD (#1744).

bin/gstack-gbrain-source-wireup

@@ -39,7 +39,7 @@
 # Depends on: bun (already a gstack dependency), gbrain, git.
 
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 CONFIG_BIN="$SCRIPT_DIR/gstack-config"

bin/gstack-hook-check

@@ -37,7 +37,7 @@
 # (needed when a hook runs TypeScript) is not found. Set GSTACK_HOOK_CHECK_BUN to
 # the bun to run (setup passes its own).
 set -u
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 LIST_ONLY=0 SETUP_FILE=""
 while [ $# -gt 1 ]; do

bin/gstack-install-verdict.sh

@@ -31,7 +31,7 @@
 # spawned sessions (ambient OpenClaw) only warn. GSTACK_ALLOW_UNSUPPORTED_RUNTIME=1
 # admits anyway and says so.
 
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 # gstack_source_root BIN_DIR — the source checkout behind an install: an
 # installed runtime root's recorded .source-path (setup _link_runtime_dists),

bin/gstack-ios-qa-daemon

@@ -21,7 +21,7 @@
 # session tokens are outstanding.
 
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 # The --help heredoc is over 512 bytes; keep it off a pipe (test/heredoc-pipe-deadlock.test.ts).
 BASH_COMPAT=50
 

bin/gstack-ios-qa-mint

@@ -10,7 +10,7 @@
 # Allowlist file: ~/.gstack/ios-qa-allowlist.json (mode 0600).
 
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 GSTACK_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"

bin/gstack-ios-qa-regen

@@ -3,7 +3,7 @@
 # package and the app-owned typed state accessors.
 
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 usage() {
   cat <<'EOF'

bin/gstack-learnings-log

@@ -6,7 +6,7 @@
 # Append-only storage. Duplicates (same key+type) are resolved at read time
 # by gstack-learnings-search ("latest winner" per key+type).
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 # Windows git-bash (#1950): pwd yields a POSIX path (/c/Users/...), which Bun
 # on Windows cannot resolve as an ES module specifier in the import below.

bin/gstack-learnings-search

@@ -8,7 +8,7 @@
 # exits 127 and a failed read exits non-zero with its stderr (#2790): "could
 # not read" must never look like "nothing recorded".
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 eval "$("$SCRIPT_DIR/gstack-slug" 2>/dev/null)"
 . "$(dirname "$0")/gstack-state-root.sh" 2>/dev/null || { echo "$0: cannot resolve the gstack state root: $(dirname "$0")/gstack-state-root.sh is missing. fix: reinstall with ./setup or /gstack-upgrade (docs/state-root.md)" >&2; exit 1; }

bin/gstack-memorable

@@ -32,7 +32,7 @@
 # Heredoc delivery guard (see bin/gstack-settings-hook for the rationale).
 BASH_COMPAT=50
 set -uo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 ROOT_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"

bin/gstack-question-log

@@ -26,7 +26,7 @@
 #
 # Append-only JSONL. Dedup is at read time in gstack-question-sensitivity --read-log.
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 # Windows git-bash (#1950): pwd yields a POSIX path (/c/Users/...), which Bun
 # on Windows cannot resolve as an ES module specifier in bun -e imports.

bin/gstack-question-preference

@@ -35,7 +35,7 @@
 # --check already ignores those prefs; storing them made --stats lie.
 # always-ask on a one-way id is fine (it agrees with the safety override).
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 ROOT_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"

bin/gstack-relink

@@ -9,7 +9,7 @@
 #   GSTACK_INSTALL_DIR — override gstack install directory
 #   GSTACK_SKILLS_DIR  — override target skills directory
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 GSTACK_CONFIG="${SCRIPT_DIR}/gstack-config"

bin/gstack-review-log

@@ -17,7 +17,7 @@
 # a model read the code. Caller-supplied binding fields are always discarded.
 # Plan-tier rows retain their legacy binding behavior.
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 export GIT_OPTIONAL_LOCKS=0
 export GIT_CONFIG_PARAMETERS="${GIT_CONFIG_PARAMETERS:+$GIT_CONFIG_PARAMETERS }'core.fsmonitor=false' 'core.untrackedCache=false'"
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"

bin/gstack-review-read

@@ -9,7 +9,7 @@
 # rows using review_freshness; legacy or uncaptured diff evidence cannot fall
 # back to HEAD equality. Plan rows are unchanged.
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 case "$(uname -s)" in
   MINGW*|MSYS*|CYGWIN*) command -v cygpath >/dev/null 2>&1 && SCRIPT_DIR="$(cygpath -m "$SCRIPT_DIR")" ;;

bin/gstack-settings-hook

@@ -69,7 +69,7 @@
 BASH_COMPAT=50
 
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 ACTION="${1:-}"
 SETTINGS_FILE="${GSTACK_SETTINGS_FILE:-${CLAUDE_CONFIG_DIR:-$HOME/.claude}/settings.json}"

bin/gstack-specialist-stats

@@ -8,7 +8,7 @@
 # Fix-range passes (scope "fix-range", #3339) are skipped: a narrowed dispatch
 # says nothing about a specialist's hit rate on a whole branch.
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 eval "$("$SCRIPT_DIR/gstack-slug" 2>/dev/null)"
 . "$(dirname "$0")/gstack-state-root.sh" 2>/dev/null || { echo "$0: cannot resolve the gstack state root: $(dirname "$0")/gstack-state-root.sh is missing. fix: reinstall with ./setup or /gstack-upgrade (docs/state-root.md)" >&2; exit 1; }

bin/gstack-team-init

@@ -18,7 +18,7 @@
 BASH_COMPAT=50
 
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 MODE="${1:-}"
 

bin/gstack-telemetry-log

@@ -21,7 +21,7 @@
 #
 # NOTE: Uses set -uo pipefail (no -e) — telemetry must never exit non-zero
 set -uo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 GSTACK_DIR="${GSTACK_DIR:-$(cd "$(dirname "$0")/.." && pwd)}"
 SCRIPT_DIR="$GSTACK_DIR/bin"

bin/gstack-timeline-log

@@ -10,7 +10,7 @@
 # Optional: branch, outcome, duration_s, session, ts.
 # Validation failure → skip silently (non-blocking).
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 eval "$("$SCRIPT_DIR/gstack-slug" 2>/dev/null)"
 . "$(dirname "$0")/gstack-state-root.sh" 2>/dev/null || { echo "$0: cannot resolve the gstack state root: $(dirname "$0")/gstack-state-root.sh is missing. fix: reinstall with ./setup or /gstack-upgrade (docs/state-root.md)" >&2; exit 1; }

bin/gstack-timeline-read

@@ -10,7 +10,7 @@
 # --branch, or an unknown argument exits 2 before any read (#1723); --help
 # prints the usage line and exits 0.
 set -euo pipefail
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 USAGE='Usage: gstack-timeline-read [--since "7 days ago"|7d|YYYY-MM-DD] [--limit N] [--branch NAME]'
 SINCE_FORMS='accepted: "<N> minute|hour|day|week|month[s] ago", "<N>h|d|w", or an ISO date YYYY-MM-DD or YYYY-MM-DDTHH:MM:SSZ'
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"

gstack-upgrade/migrations/v1.86.0.0.sh

@@ -5,7 +5,7 @@
 # shared old renders are retired. This post-setup pass repairs missed upgrades.
 # Idempotent and non-fatal: foreign entries and failed replacements stay intact.
 set -u
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 INSTALL_DIR="${GSTACK_INSTALL_DIR:-$HOME/.claude/skills/gstack}"
 if [ -f "$INSTALL_DIR/bin/gstack-migrate-claude-code" ] && command -v bun >/dev/null 2>&1; then
   bun --no-env-file --config="${GSTACK_BUN_CONFIG:-/dev/null}" "$INSTALL_DIR/bin/gstack-migrate-claude-code" --install-dir "$INSTALL_DIR" || true

hosts/claude/hooks/auq-error-fallback-hook

@@ -3,6 +3,6 @@
 # wrapper makes the TypeScript hook executable via bun. Settings.json
 # references this file directly.
 set -e
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 HERE="$(cd "$(dirname "$0")" && pwd)"
 exec bun --no-env-file --config="${GSTACK_BUN_CONFIG:-/dev/null}" "$HERE/auq-error-fallback-hook.ts"

hosts/claude/hooks/memorable-user-prompt-hook

@@ -12,7 +12,7 @@
 # vendor process running with the prompt on its stdin. Forwarded, the signal
 # reaches the .ts, which kills the vendor's process group on its way out.
 # `<&0` keeps stdin: bash hands background jobs /dev/null otherwise.
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 HERE="$(cd "$(dirname "$0")" && pwd)" || exit 0
 bun --no-env-file --config="${GSTACK_BUN_CONFIG:-/dev/null}" "$HERE/memorable-user-prompt-hook.ts" <&0 &
 _child=$!

hosts/claude/hooks/question-log-hook

@@ -3,6 +3,6 @@
 # wrapper makes the TypeScript hook executable via bun. Settings.json
 # references this file directly.
 set -e
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 HERE="$(cd "$(dirname "$0")" && pwd)"
 exec bun --no-env-file --config="${GSTACK_BUN_CONFIG:-/dev/null}" "$HERE/question-log-hook.ts"

hosts/claude/hooks/question-preference-hook

@@ -3,6 +3,6 @@
 # wrapper makes the TypeScript hook executable via bun. Settings.json
 # references this file directly.
 set -e
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 HERE="$(cd "$(dirname "$0")" && pwd)"
 exec bun --no-env-file --config="${GSTACK_BUN_CONFIG:-/dev/null}" "$HERE/question-preference-hook.ts"

hosts/claude/hooks/timeline-stop-hook

@@ -5,7 +5,7 @@
 #
 # FAIL-OPEN (F5): a Stop-event telemetry repair must never block the session.
 # Every failure path — bun missing, script crash — still exits 0.
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 HERE="$(cd "$(dirname "$0")" && pwd)" || exit 0
 bun --no-env-file --config="${GSTACK_BUN_CONFIG:-/dev/null}" "$HERE/timeline-stop-hook.ts" || true
 exit 0

lib/bun-isolation.ts

@@ -6,8 +6,8 @@
  * code under review. Every Bun gstack starts passes --no-env-file and an empty
  * --config: shebangs and skill prose spell it
  * `bun --no-env-file --config=/dev/null`, shipped shell files spell
- * `--config="${GSTACK_BUN_CONFIG:-/dev/null}"` (NUL under MINGW, MSYS and
- * Cygwin, #3415), TypeScript spawns use bunIsolationArgs().
+ * `--config="${GSTACK_BUN_CONFIG:-/dev/null}"` (NUL when OSTYPE is msys or
+ * cygwin, #3415), TypeScript spawns use bunIsolationArgs().
  * test/bun-entry-isolation.test.ts holds every entry point to that form.
  *
  * POSIX passes /dev/null. Native Windows has no /dev/null and `--config=NUL`

plan-ceo-review/bin/mode-handoff-hook

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 # Bash shim — Claude Code runs hook commands through /bin/sh; this runs the
 # TypeScript hook with bun.
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 HERE="$(cd "$(dirname "$0")" && pwd)"
 exec bun --no-env-file --config="${GSTACK_BUN_CONFIG:-/dev/null}" "$HERE/mode-handoff-hook.ts"

scripts/build-cso.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 set -eu
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 
 CSO_BUILD_ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 cd "$CSO_BUILD_ROOT"

setup

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 # gstack setup — build browser binary + register skills with Claude Code / Codex
 set -e
-GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac
+GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac
 umask 077  # Restrict new files to owner-only (0o600 files, 0o700 dirs)
 
 # Heredoc delivery guard. bash 5.2+ writes a heredoc body <=64KiB through a

test/bun-config-shell-bins.test.ts

@@ -1,7 +1,8 @@
 /**
  * #3415: gstack's shell bins start Bun with
  * --config="${GSTACK_BUN_CONFIG:-/dev/null}", and each defines
- * GSTACK_BUN_CONFIG as NUL under MINGW, MSYS and Cygwin. Native bun.exe cannot
+ * GSTACK_BUN_CONFIG as NUL when OSTYPE is msys or cygwin (Git Bash, MSYS2,
+ * Cygwin). Native bun.exe cannot
  * open /dev/null (EINVAL), so a Windows bash with MSYS path conversion off
  * (MSYS_NO_PATHCONV=1, MSYS2_ARG_CONV_EXCL=*) made the literal spelling fail:
  * the record bins wrote nothing, and gstack-timeline-log still exited 0.
@@ -9,10 +10,10 @@
  * On every platform the free lanes run, windows-latest included, the record
  * bins run through lib/script-invocation.ts with conversion off in a hostile
  * repository: each writes its record, and the repository's bunfig.toml preload
- * and .env never load. On POSIX a simulated Windows bash (uname reporting
- * MINGW64, a bun that rejects /dev/null the way bun.exe does) reproduces the
- * bug; its controls, with uname reporting Linux, show each bin fails loudly
- * with nothing written instead of exiting 0.
+ * and .env never load. On POSIX a simulated Windows bash (OSTYPE=msys, a bun
+ * that rejects /dev/null the way bun.exe does) reproduces the bug; its
+ * controls, without OSTYPE=msys, show each bin fails loudly with nothing
+ * written instead of exiting 0.
  */
 import { afterAll, beforeAll, describe, expect, test } from 'bun:test';
 import { spawnSync } from 'node:child_process';
@@ -29,8 +30,7 @@ let repo = '';
 let stateRoot = '';
 let evilRoot = '';
 let preloadMarker = '';
-let fakeWindows = '';
-let fakeBunOnly = '';
+let fakeBun = '';
 
 const BINS: Array<{ bin: string; input: string; log: string }> = [
   { bin: 'gstack-review-log', log: 'main-reviews.jsonl', input: JSON.stringify({ skill: 'plan-eng-review', timestamp: '2026-10-25T00:00:00Z', status: 'clean', unresolved: 0, critical_gaps: 0, issues_found: 0, mode: 'FULL_REVIEW', commit: 'abc1234' }) },
@@ -39,16 +39,16 @@ const BINS: Array<{ bin: string; input: string; log: string }> = [
   { bin: 'gstack-timeline-log', log: 'timeline.jsonl', input: JSON.stringify({ skill: 'review', event: 'started', branch: 'main' }) },
 ];
 
-function env(pathPrefix?: string): NodeJS.ProcessEnv {
+function env(pathPrefix?: string, extra: Record<string, string> = {}): NodeJS.ProcessEnv {
   const out: NodeJS.ProcessEnv = {};
-  for (const [k, v] of Object.entries(process.env)) if (!/^(GSTACK_|MSYS)/.test(k)) out[k] = v;
+  for (const [k, v] of Object.entries(process.env)) if (!/^(GSTACK_|MSYS|OSTYPE$)/.test(k)) out[k] = v;
   const PATH = Object.keys(out).find(k => k.toUpperCase() === 'PATH') ?? 'PATH';
   if (pathPrefix) out[PATH] = pathPrefix + path.delimiter + (out[PATH] ?? '');
-  return { ...out, HOME: path.join(tmp, 'home'), GSTACK_STATE_ROOT: stateRoot, MSYS_NO_PATHCONV: '1', MSYS2_ARG_CONV_EXCL: '*' };
+  return { ...out, HOME: path.join(tmp, 'home'), GSTACK_STATE_ROOT: stateRoot, MSYS_NO_PATHCONV: '1', MSYS2_ARG_CONV_EXCL: '*', ...extra };
 }
 
-function run(bin: string, input: string, pathPrefix?: string) {
-  return runScriptSync(path.join(ROOT, 'bin', bin), [input], { cwd: repo, env: env(pathPrefix), encoding: 'utf8', timeout: 60_000 });
+function run(bin: string, input: string, pathPrefix?: string, extra: Record<string, string> = {}) {
+  return runScriptSync(path.join(ROOT, 'bin', bin), [input], { cwd: repo, env: env(pathPrefix, extra), encoding: 'utf8', timeout: 60_000 });
 }
 
 function records(log: string): string[] {
@@ -84,26 +84,21 @@ beforeAll(() => {
   fs.writeFileSync(path.join(repo, 'preload.ts'), `require('fs').writeFileSync(${JSON.stringify(preloadMarker)}, 'ran');\n`);
   fs.writeFileSync(path.join(repo, 'bunfig.toml'), 'preload = ["./preload.ts"]\n');
   if (IS_WINDOWS) return;
-  fakeWindows = path.join(tmp, 'fake-windows');
-  fakeBunOnly = path.join(tmp, 'fake-bun-only');
-  for (const dir of [fakeWindows, fakeBunOnly]) {
-    fs.mkdirSync(dir);
-    writeExec(path.join(dir, 'bun'), [
-      '#!/usr/bin/env bash',
-      'a=()',
-      'for x in "$@"; do',
-      '  case "$x" in',
-      '    --config=/dev/null) echo "EINVAL: Invalid argument (open())" >&2; echo "while reading config \\"/dev/null\\"" >&2; exit 1 ;;',
-      '    --config=NUL) a+=(--config=/dev/null) ;;',
-      '    *) a+=("$x") ;;',
-      '  esac',
-      'done',
-      `exec ${JSON.stringify(process.execPath)} "\${a[@]}"`,
-      '',
-    ].join('\n'));
-  }
-  writeExec(path.join(fakeWindows, 'uname'), '#!/usr/bin/env bash\n[ "$1" = -s ] && { echo MINGW64_NT-10.0-26100; exit 0; }\nexec /usr/bin/uname "$@"\n');
-  writeExec(path.join(fakeWindows, 'cygpath'), '#!/usr/bin/env bash\nprintf "%s\\n" "$2"\n');
+  fakeBun = path.join(tmp, 'fake-bun');
+  fs.mkdirSync(fakeBun);
+  writeExec(path.join(fakeBun, 'bun'), [
+    '#!/usr/bin/env bash',
+    'a=()',
+    'for x in "$@"; do',
+    '  case "$x" in',
+    '    --config=/dev/null) echo "EINVAL: Invalid argument (open())" >&2; echo "while reading config \\"/dev/null\\"" >&2; exit 1 ;;',
+    '    --config=NUL) a+=(--config=/dev/null) ;;',
+    '    *) a+=("$x") ;;',
+    '  esac',
+    'done',
+    `exec ${JSON.stringify(process.execPath)} "\${a[@]}"`,
+    '',
+  ].join('\n'));
 });
 
 afterAll(() => { if (tmp) fs.rmSync(tmp, { recursive: true, force: true }); });
@@ -143,7 +138,7 @@ describe.skipIf(IS_WINDOWS)('#3415: simulated Windows bash (POSIX hosts)', () =>
   for (const { bin, input, log } of BINS) {
     test(`${bin} passes NUL and writes its record`, () => {
       resetState();
-      const r = run(bin, input, fakeWindows);
+      const r = run(bin, input, fakeBun, { OSTYPE: 'msys' });
       expect(r.stderr).not.toContain('EINVAL');
       expect(r.status).toBe(0);
       expect(records(log).length).toBe(1);
@@ -152,7 +147,7 @@ describe.skipIf(IS_WINDOWS)('#3415: simulated Windows bash (POSIX hosts)', () =>
 
     test(`control: when Bun rejects the config, ${bin} fails loudly and writes nothing`, () => {
       resetState();
-      const r = run(bin, input, fakeBunOnly);
+      const r = run(bin, input, fakeBun);
       expect(r.stderr).toContain('EINVAL');
       expect(r.status).not.toBe(0);
       expect(records(log)).toEqual([]);

test/bun-entry-isolation.test.ts

@@ -30,7 +30,7 @@ const ROOT = path.resolve(import.meta.dir, '..');
 const FLAGS = '--no-env-file --config=/dev/null';
 const ISOLATED_SHEBANG = `#!/usr/bin/env -S bun ${FLAGS}`;
 const SHELL_FLAGS = '--no-env-file --config="${GSTACK_BUN_CONFIG:-/dev/null}"';
-const CONFIG_DEF = 'GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac';
+const CONFIG_DEF = 'GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac';
 
 const TRACKED = spawnSync('git', ['ls-files', '-z'], { cwd: ROOT, encoding: 'utf8', timeout: 30_000 }).stdout.split('\0').filter(Boolean)
   .filter(f => !/(^|\/)test\//.test(f) && fs.existsSync(path.join(ROOT, f)) && fs.statSync(path.join(ROOT, f)).isFile());

test/bun-isolation-launch.test.ts

@@ -18,7 +18,7 @@ import { bunIsolationArgs } from '../lib/bun-isolation';
 import { bashCommandInvocation } from '../lib/script-invocation';
 
 const PRINT = 'console.log("env=" + (process.env.GSTACK_LAUNCH_PROBE ?? "unset"))';
-const CONFIG_DEF = 'GSTACK_BUN_CONFIG=/dev/null; case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) GSTACK_BUN_CONFIG=NUL ;; esac';
+const CONFIG_DEF = 'GSTACK_BUN_CONFIG=/dev/null; case "${OSTYPE:-}" in msys*|cygwin*) GSTACK_BUN_CONFIG=NUL ;; esac';
 const NO_PATHCONV = { MSYS_NO_PATHCONV: '1', MSYS2_ARG_CONV_EXCL: '*' };
 let project = '';
 let preloadMarker = '';

test/plan-mode-preamble-render.test.ts

@@ -16,7 +16,7 @@ import * as path from 'path';
 
 const ROOT = path.resolve(import.meta.dir, '..');
 const PLAN_ARG = '${_PLAN_MODE_ARG:+"$_PLAN_MODE_ARG"}';
-const GENERATOR = /(?:\bbun(?: --no-env-file --config=\/dev\/null)?|\bbun_cmd|_gstack_render_bun) run (?:gen:skill-docs(?::user)?|scripts\/gen-skill-docs\.ts) --[a-z]/;
+const GENERATOR = /(?:\bbun(?: --no-env-file --config=(?:\/dev\/null|"\$\{GSTACK_BUN_CONFIG:-\/dev\/null\}"))?|\bbun_cmd|_gstack_render_bun) run (?:gen:skill-docs(?::user)?|scripts\/gen-skill-docs\.ts) --[a-z]/;
 const CONFIG_READ = '[ "$("$GSTACK_CONFIG" get plan_mode_preamble 2>/dev/null || true)" != off ] || _PLAN_MODE_ARG="--plan-mode=off"';
 
 /** Generator invocations in a file: not comments, and not echoed or logged instructions. */