E6: gbrain-refresh hands the detection file to Python on stdin

Under Git Bash, a native Windows Python first on PATH cannot open an MSYS
/c/... path, so gbrain-refresh always summarized the detection as
'local-status: unknown' and brain-aware blocks were suppressed. bash now
opens the file and Python reads stdin; the grep fallback without Python is
unchanged. Verified on Linux with a stub Python that refuses path opens; not
run on Windows.

Co-authored-by: maxpetrusenkoagent <max.petrusenko.agent@gmail.com>

bin/gstack-config

@@ -693,10 +693,12 @@ case "${1:-}" in
 
     # Summarize for the user. Use python (already required elsewhere) to
     # parse the JSON portably; fall back to grep if python is unavailable.
+    # The file goes in on stdin (E6, #1967): bash opens the path, so a native
+    # Windows Python under Git Bash never has to resolve an MSYS /c/... path.
     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)
+      STATUS=$("$PYTHON_CMD" -c "import json,sys; d=json.load(sys.stdin); print(d.get('gbrain_local_status','unknown'))" < "$DETECTION_FILE" 2>/dev/null || echo unknown)
+      VERSION=$("$PYTHON_CMD" -c "import json,sys; d=json.load(sys.stdin); print(d.get('gbrain_version') or 'unknown')" < "$DETECTION_FILE" 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/')

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

@@ -0,0 +1,50 @@
+/**
+ * E6 (#1967): under Git Bash on Windows, a native Windows Python first on PATH
+ * cannot open an MSYS-style /c/... path, so gbrain-refresh always summarized
+ * the detection file as "local-status: unknown". The file is now read by bash
+ * and handed to Python on stdin. The stub Python below refuses any path
+ * argument, as a native Windows Python does with an MSYS path, and parses stdin.
+ */
+import { afterEach, beforeEach, describe, expect, test } from 'bun:test';
+import { spawnSync } from 'child_process';
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
+
+const ROOT = path.resolve(import.meta.dir, '..');
+let tmp: string;
+let binDir: string;
+let home: string;
+
+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 });
+  for (const f of ['gstack-config', 'gstack-state-root.sh']) {
+    fs.copyFileSync(path.join(ROOT, 'bin', f), path.join(binDir, f));
+    fs.chmodSync(path.join(binDir, f), 0o755);
+  }
+  fs.writeFileSync(path.join(binDir, 'gstack-gbrain-detect'),
+    `#!/usr/bin/env bash\nprintf '%s\\n' '{"gbrain_on_path":true,"gbrain_local_status":"no-config","gbrain_version":"0.35.8.0"}'\n`, { mode: 0o755 });
+  // A Python that cannot open() the state path but reads stdin, like native
+  // Windows Python handed an MSYS path. Bun stands in for its JSON parse.
+  fs.writeFileSync(path.join(binDir, 'python3'), `#!/usr/bin/env bash
+case "$2" in *"open("*) echo "FileNotFoundError: [Errno 2] No such file or directory" >&2; exit 1 ;; esac
+exec ${JSON.stringify(process.execPath)} -e 'const d = JSON.parse(require("fs").readFileSync(0, "utf8")); console.log(process.argv[1].includes("gbrain_version") ? (d.gbrain_version || "unknown") : (d.gbrain_local_status || "unknown"))' "$2"
+`, { mode: 0o755 });
+});
+afterEach(() => { fs.rmSync(tmp, { recursive: true, force: true }); });
+
+describe('gstack-config gbrain-refresh (E6)', () => {
+  test('reads the detection file through stdin, so the status is not masked as unknown', () => {
+    const r = spawnSync('bash', [path.join(binDir, 'gstack-config'), 'gbrain-refresh'], {
+      encoding: 'utf8', timeout: 30_000,
+      env: { PATH: `${binDir}:${process.env.PATH ?? '/usr/bin:/bin'}`, HOME: home, GSTACK_HOME: home, GSTACK_STATE_ROOT: home },
+    });
+    expect(r.status, r.stderr).toBe(0);
+    expect(r.stdout).toContain('local-status: no-config');
+    expect(r.stdout).not.toContain('local-status: unknown');
+  });
+});