{"record":{"id":"b3d05b892df4fc5c","repo":"phacility/phabricator","slug":"failed-to-s","errorCode":null,"errorMessage":"Failed to %s!","messagePattern":"Failed to (.+?)!","errorType":"exception","errorClass":"Exception","httpStatus":null,"severity":"critical","filePath":"src/applications/aphlict/management/PhabricatorAphlictManagementWorkflow.php","lineNumber":456,"sourceCode":"/* -(  Commands  )----------------------------------------------------------- */\n\n\n  final protected function executeStartCommand() {\n    $console = PhutilConsole::getConsole();\n    $this->willLaunch();\n\n    $log = $this->getOverseerLogPath();\n    if ($log !== null) {\n      echo tsprintf(\n        \"%s\\n\",\n        pht(\n          'Writing logs to: %s',\n          $log));\n    }\n\n    $pid = pcntl_fork();\n    if ($pid < 0) {\n      throw new Exception(\n        pht(\n          'Failed to %s!',\n          'fork()'));\n    } else if ($pid) {\n      $console->writeErr(\"%s\\n\", pht('Aphlict Server started.'));\n      exit(0);\n    }\n\n    // Redirect process errors to the error log. If we do not do this, any\n    // error the `aphlict` process itself encounters vanishes into thin air.\n    if ($log !== null) {\n      ini_set('error_log', $log);\n    }\n\n    // When we fork, the child process will inherit its parent's set of open\n    // file descriptors. If the parent process of bin/aphlict is waiting for\n    // bin/aphlict's file descriptors to close, it will be stuck waiting on\n    // the daemonized process. (This happens if e.g. bin/aphlict is started","sourceCodeStart":438,"sourceCodeEnd":474,"githubUrl":"https://github.com/phacility/phabricator/blob/5720a38cfe95b00ca4be5016dd0d2f3195f4fa04/src/applications/aphlict/management/PhabricatorAphlictManagementWorkflow.php#L438-L474","documentation":"Thrown in the daemonization path when pcntl_fork() returns a negative value, i.e. the OS refused to create a child process. This is an environment-level failure (not config), reported by the parent CLI process before it exits; the '%s' in the template is filled with 'fork()'.","triggerScenarios":"Hitting RLIMIT_NPROC (per-user process limit) or system-wide PID exhaustion; forking denied by a container/seccomp policy that blocks clone(). Debug mode (--debug/--foreground) skips the fork and avoids the call.","commonSituations":"Shared hosts or cgroup-limited containers with tight ulimit -u; systemd service without TasksMax headroom; security-hardened containers blocking fork.","solutions":["Check limits: ulimit -u and systemd's TasksMax; raise them for the aphlict service user or unit","Free headroom by stopping leaked processes, or reboot to clear PID exhaustion","Run `bin/aphlict debug --client ... --admin ...` in the foreground (no fork) to confirm the failure is fork-specific, and consider a supervisor running it in foreground mode"],"exampleFix":"# before: pcntl_fork() fails under tight limits\n$ ulimit -u\n# raise limit (systemd): [Service] TasksMax=512\n# after: bin/aphlict start forks successfully","handlingStrategy":"fallback","validationCode":"// Pre-flight: can we fork at all?\n$test = pcntl_fork();\nif ($test < 0) {\n  throw new Exception('pcntl_fork unavailable: check ulimit -u / TasksMax');\n}\nif ($test === 0) { exit(0); } // child exits immediately\npcntl_waitpid($test, $status);","typeGuard":null,"tryCatchPattern":"try {\n  launch_daemonized($argv);\n} catch (Exception $ex) {\n  if (preg_match('/fork/', $ex->getMessage())) {\n    // fallback: run in foreground under a supervisor instead\n    launch_foreground($argv);\n  }\n}","preventionTips":["Size TasksMax/ulimit -u with headroom for the fork","Run aphlict in --debug foreground mode under systemd/supervisord to sidestep daemonization entirely"],"tags":["aphlict","process-management","pcntl","fork","system-limits","phabricator"],"backgroundTag":"process-fork-failure","analyzedSha":"5720a38cfe95b00ca4be5016dd0d2f3195f4fa04","analyzedAt":"2026-08-21T05:07:25.672Z","schemaVersion":2},"datasetVersion":"2026-08-21T11:28:35.574Z"}