Crash dump

About crash dumps

NZBGet contains bugs. Some of them causes program crashes. The bugs have to be found and eliminated. NZBGet supports two instruments to help with this:

• Call stack traces - when option CrashTrace is active the program intercepts the crash and saves the call stack trace into log-file. The call stack lets developer find the exact place of the source code where the crash happened. Sometimes this is enough to find the bug.

• Memory dumps - when a crash happens the system can save program memory state into a file. The memory dump can then be loaded into debugger and analyzed. It includes the information about call stack (similar to the call stack trace above) but also includes values of all program variables, which is a big help.

  NZBGet supports creating of crash dumps on Windows and Linux.

Windows

Step 1. Configure Windows to create crash dumps

Windows contains an instrument called Windows Error Reporting, which can create memory dumps when programs crash. This feature is not enabled by default.

MSDN-article Collecting User-Mode Dumps explains in detail how to enable and configure the feature.

In short, your need:

• Open Registry editor regedit.exe;
• Create key (folder) HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Windows Error Reporting\LocalDumps;
• Create value DumpType of type REG_DWORD with value 2 (full dump).

Memory dumps will be saved into %LOCALAPPDATA%\CrashDumps by default but you can configure other folder if necessary, as explained in MSDN-article linked above.

Step 2. Install debug version of NZBGet

• Download debug version of NZBGet: latest stable or latest testing. You need at least v19.1.
• Install it over your existing NZBGet installation. Your configuration will be preserved.
• Start NZBGet, open settings page in web-interface and set option CrashTrace=no in section LOGGING.
• Save settings and shutdown NZBGet.

Step 3. Test if crash dumps are created

• In Windows Explorer open directory where NZBGet is installed, by default C:\Program Files (x86)\NZBGet;
• Double click on nzbget-command-shell.bat (the extension .bat may be hidden depending on Windows Explorer settings). A command prompt should be opened.
• Type command

  nzbget.exe -B trace 1
  

This command causes NZBGet to crash. At this moment Windows should display a message about crashed program and write crash dump. Check directory %LOCALAPPDATA%\CrashDumps. Open Windows Explorer and put that string into address bar, followed by Enter-key, which should navigate you to the folder.

Step 4. Activate all logging

Now you can start NZBGet and wait for it to crash. To help with debugging it’s also recommended to activate all logging options: DebugTarget=log, DetailTarget=log (or both) etc.

Step 5. Upload crash dump

When you have the crash dump put it and the log-file into an archive (rar, zip, 7z, etc.) and upload it into Google Drive, MS OneDrive, Dropbox or whatever site you prefer and share it with NZBGet developer.

Linux

Step 1. Install debug version of NZBGet

• Download debug version of NZBGet: latest stable or latest testing.
• Install it over your existing NZBGet installation. Your configuration will be preserved.
• Start NZBGet, open settings page in web-interface and set option CrashTrace=no and CrashDump=yes in section LOGGING.
• Save settings and shutdown NZBGet.

Step 2. Test if crash dumps are created

Open terminal and type command

/path/to/nzbget -B trace 1

This command causes NZBGet to crash. The system should display message:

Segmentation fault (core dumped)

From the message “core dumped” you know the core-file was written.

Now you have to find out where the system has put the file. It can be in current directory or in a special directory for core files. Try googling for “where linux saves core files” (replace “linux” with your Linux version).

Step 3. Activate all logging

Now you can start NZBGet and wait for it to crash. To help with debugging it’s also recommended to activate all logging options: DebugTarget=log, DetailTarget=log (or both) etc.

Step 4. Upload crash dump

When you have the crash dump put it and the log-file into an archive (rar, zip, 7z, etc.) and upload it into Google Drive, MS OneDrive, Dropbox or whatever site you prefer and share it with NZBGet developer.