fix(multiuser-test): diagnose SSH failure with timeout and debug output

Author: yajo

checks/multiuser/default.nix

@@ -36,10 +36,13 @@ pkgs.testers.runNixOSTest {
       for user in ("alice", "bob", "root"):
         code, output = controller.execute(
           fr"""
+          set -x
+          sudo -nu {user} -- test -f "$HOME/.ssh/id_rsa" && echo "key exists" || echo "NO KEY"
           sudo -nu {user} -- ${lib.getExe nodes.target01.lollypops.deployment.ssh.login} whoami
           """,
-          timeout=10,
+          timeout=60,
         )
+        print(f"user={user} code={code} output={output!r}")
         t.assertEqual(output.strip(), user)
     '';
 }