openjdk/jdk · error

ERROR: Can't open replay file

Error message

ERROR: Can't open replay file %s

What it means

ciReplay (the -XX:+ReplayCompiles / -XX:ReplayDataFile=<file> machinery that replays a recorded compilation) failed to open the replay data file: CompileReplay's constructor does os::fopen(filename, "rt") and the result is null. It only prints the error — execution continues and parsing of the null stream fails immediately after, so replay silently does nothing.

Solutions

1. Check that the replay data file exists at the exact path passed to -XX:ReplayDataFile (or replay_pid<pid>.log in the cwd for the default)
2. Use an absolute path: -XX:ReplayDataFile=/abs/path/replay_pid123.log
3. Verify read permissions on the file for the user running the JVM
4. If the file was produced by a crashed process, re-run the original failing command from the directory where the crash happened so the relative default path resolves

Example fix

# before
java -XX:+ReplayCompiles -XX:ReplayDataFile=replay_pid123.log Main
# (run from wrong cwd -> file not found)

# after
java -XX:+ReplayCompiles -XX:ReplayDataFile=/home/user/crash/replay_pid123.log Main

# Before running replay, verify the data file:
REPLAY=/abs/path/replay_pid$$.log
[ -f "$REPLAY" ] && [ -r "$REPLAY" ] || { echo "missing replay file $REPLAY" >&2; exit 2; }
java -XX:+ReplayCompiles -XX:ReplayDataFile="$REPLAY" -Xbatch Main

When it happens

Trigger: Running java with -XX:+ReplayCompiles (or ciReplay::replay_impl triggered via the replay task) where the replay data file (default replay_pid<pid>.log, or the file named by -XX:ReplayDataFile=) does not exist, is not readable, or the path is relative to a different working directory than expected.

Common situations: After a JVM crash the hs-err file asks to run 'java -XX:+ReplayCompiles -XX:ReplayDataFile=replay_pid123.log ...' but the user runs from a different cwd; the replay file was cleaned up; permissions issues in sandboxed CI; typo in the ReplayDataFile path.

Related errors

• Error parsing long
• Error Context: >>>%c<<<
• AGENT_ERROR_STARTFAIL
• ERROR: More than one register has been assigned…
• error: node is null

AI-assisted analysis of openjdk/jdk@88dfb74bbe (2026-08-14). Data as JSON: /api/errors/0bf0219ea983992c. Report an issue: GitHub.

Appendix: source

Thrown at src/hotspot/share/ci/ciReplay.cpp:151

  char* _bufptr;
  char* _buffer;
  int   _buffer_length;
  ReallocMark _nesting; // Safety checks for arena reallocation

  // "compile" data
  ciKlass* _iklass;
  Method*  _imethod;
  int      _entry_bci;
  int      _comp_level;

 public:
  CompileReplay(const char* filename, TRAPS) {
    _thread = THREAD;
    _loader = Handle(_thread, SystemDictionary::java_system_loader());

    _stream = os::fopen(filename, "rt");
    if (_stream == nullptr) {
      fprintf(stderr, "ERROR: Can't open replay file %s\n", filename);
    }

    _ci_inline_records = nullptr;
    _error_message = nullptr;

    _buffer_length = 32;
    _buffer = NEW_RESOURCE_ARRAY(char, _buffer_length);
    _bufptr = _buffer;

    _imethod = nullptr;
    _iklass  = nullptr;
    _entry_bci  = 0;
    _comp_level = 0;
    _version = 0;

    test();
  }

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