fix(gbrain): parse refresh detection without Python path dependency

bin/gstack-config

@@ -381,18 +381,20 @@ case "${1:-}" in
     fi
     mv "$DETECTION_FILE.tmp" "$DETECTION_FILE"
 
-    # Summarize for the user. Use python (already required elsewhere) to
-    # parse the JSON portably; fall back to grep if python is unavailable.
-    PYTHON_CMD=$(command -v python3 || command -v python || true)
-    if [ -n "$PYTHON_CMD" ]; then
-      STATUS=$("$PYTHON_CMD" -c "import json,sys; d=json.load(open('$DETECTION_FILE')); print(d.get('gbrain_local_status','unknown'))" 2>/dev/null || echo unknown)
-      VERSION=$("$PYTHON_CMD" -c "import json,sys; d=json.load(open('$DETECTION_FILE')); print(d.get('gbrain_version') or 'unknown')" 2>/dev/null || echo unknown)
-    else
-      STATUS=$(grep -o '"gbrain_local_status":[[:space:]]*"[^"]*"' "$DETECTION_FILE" | sed 's/.*"\([^"]*\)"$/\1/')
-      VERSION=$(grep -o '"gbrain_version":[[:space:]]*"[^"]*"' "$DETECTION_FILE" | sed 's/.*"\([^"]*\)"$/\1/')
-      [ -z "$STATUS" ] && STATUS=unknown
-      [ -z "$VERSION" ] && VERSION=unknown
+    # Summarize for the user. Prefer the shell parser because Git Bash can put
+    # native Windows Python first on PATH, and that Python cannot open MSYS-style
+    # /c/... paths. Keep Python only as a fallback if the flat-field grep misses.
+    STATUS=$(grep -o '"gbrain_local_status":[[:space:]]*"[^"]*"' "$DETECTION_FILE" | sed 's/.*"\([^"]*\)"$/\1/' | head -1 || true)
+    VERSION=$(grep -o '"gbrain_version":[[:space:]]*"[^"]*"' "$DETECTION_FILE" | sed 's/.*"\([^"]*\)"$/\1/' | head -1 || true)
+    if [ -z "$STATUS" ] || [ -z "$VERSION" ]; then
+      PYTHON_CMD=$(command -v python3 || command -v python || true)
+      if [ -n "$PYTHON_CMD" ]; then
+        [ -z "$STATUS" ] && STATUS=$("$PYTHON_CMD" -c "import json,sys; d=json.load(open('$DETECTION_FILE')); print(d.get('gbrain_local_status','unknown'))" 2>/dev/null || echo unknown)
+        [ -z "$VERSION" ] && VERSION=$("$PYTHON_CMD" -c "import json,sys; d=json.load(open('$DETECTION_FILE')); print(d.get('gbrain_version') or 'unknown')" 2>/dev/null || echo unknown)
+      fi
     fi
+    [ -z "$STATUS" ] && STATUS=unknown
+    [ -z "$VERSION" ] && VERSION=unknown
 
     case "$STATUS" in
       ok)

test/gstack-config-gbrain-refresh.test.ts

@@ -0,0 +1,69 @@
+/**
+ * Regression coverage for #1967: Git Bash on Windows can put a native Windows
+ * Python first on PATH. That Python cannot open MSYS-style /c/... paths, so
+ * gstack-config must not let a Python JSON parse failure mask a valid detection
+ * file as local-status: unknown.
+ */
+import { describe, test, expect, beforeEach, afterEach } from "bun:test";
+import * as fs from "fs";
+import * as os from "os";
+import * as path from "path";
+import { spawnSync } from "child_process";
+
+const ROOT = path.resolve(import.meta.dir, "..");
+const SOURCE_CONFIG = path.join(ROOT, "bin", "gstack-config");
+
+let tmp: string;
+let binDir: string;
+let home: string;
+
+function writeExecutable(file: string, content: string) {
+  fs.writeFileSync(file, content, { mode: 0o755 });
+}
+
+function runGbrainRefresh(): { code: number; out: string; err: string } {
+  const r = spawnSync(path.join(binDir, "gstack-config"), ["gbrain-refresh"], {
+    encoding: "utf8",
+    env: {
+      ...process.env,
+      HOME: home,
+      GSTACK_HOME: home,
+      GSTACK_STATE_ROOT: home,
+      PATH: `${binDir}${path.delimiter}${process.env.PATH ?? ""}`,
+    },
+  });
+  return { code: r.status ?? 0, out: r.stdout ?? "", err: r.stderr ?? "" };
+}
+
+beforeEach(() => {
+  tmp = fs.mkdtempSync(path.join(os.tmpdir(), "gbrain-refresh-"));
+  binDir = path.join(tmp, "bin");
+  home = path.join(tmp, "home");
+  fs.mkdirSync(binDir, { recursive: true });
+  fs.mkdirSync(home, { recursive: true });
+  fs.copyFileSync(SOURCE_CONFIG, path.join(binDir, "gstack-config"));
+  fs.chmodSync(path.join(binDir, "gstack-config"), 0o755);
+});
+
+afterEach(() => {
+  fs.rmSync(tmp, { recursive: true, force: true });
+});
+
+describe("gstack-config gbrain-refresh", () => {
+  test("does not report unknown when PATH python cannot open the detection file", () => {
+    writeExecutable(
+      path.join(binDir, "gstack-gbrain-detect"),
+      `#!/usr/bin/env bash\nprintf '%s\\n' '{"gbrain_on_path":true,"gbrain_local_status":"ok","gbrain_version":"0.35.8.0"}'\n`,
+    );
+    writeExecutable(
+      path.join(binDir, "python3"),
+      `#!/usr/bin/env bash\necho "FileNotFoundError: native Windows Python cannot open this MSYS path" >&2\nexit 1\n`,
+    );
+
+    const r = runGbrainRefresh();
+
+    expect(r.code).toBe(0);
+    expect(r.out).toContain("Detected gbrain v0.35.8.0");
+    expect(r.out).not.toContain("local-status: unknown");
+  });
+});