fix(core): Handle PTY spawn errors in macOS sandbox (#11539)

packages/cli/src/utils/sandbox-macos-permissive-open.sb

@@ -22,4 +22,6 @@
     (literal "/dev/stdout")
     (literal "/dev/stderr")
     (literal "/dev/null")
+    (literal "/dev/ptmx")
+    (regex #"^/dev/ttys[0-9]*$")
 )

packages/core/src/services/shellExecutionService.ts

@@ -678,6 +678,14 @@ export class ShellExecutionService {
       return { pid: ptyProcess.pid, result };
     } catch (e) {
       const error = e as Error;
+      if (error.message.includes('posix_spawnp failed')) {
+        onOutputEvent({
+          type: 'data',
+          chunk:
+            '[GEMINI_CLI_WARNING] PTY execution failed, falling back to child_process. This may be due to sandbox restrictions.\n',
+        });
+        throw e;
+      } else {
         return {
           pid: undefined,
           result: Promise.resolve({
@@ -693,6 +701,7 @@ export class ShellExecutionService {
         };
       }
     }
+  }
 
   /**
    * Writes a string to the pseudo-terminal (PTY) of a running process.