💥 How to customize warnings and errors

After Borg runs, it indicates whether it succeeded via its exit code, a numeric ID indicating success, warning, or error. borgmatic consumes this exit code to decide how to respond. By default, Borg errors (and some warnings) result in a borgmatic error, while Borg successes don't.

New in borgmatic version 2.1.0 borgmatic elevates most Borg warnings to errors by default. For instance, if a source directory is missing during backup, Borg indicates that with a warning exit code (107). And starting in borgmatic 2.1.0, that exit code is considered an error, so you'll actually find out about missing files.

With Borg version 1.4+ If the default behavior isn't sufficient for your needs, you can customize how borgmatic interprets Borg's exit codes.

For instance, this borgmatic configuration elevates a Borg warning about source files changes during backup (exit code 100)—and only those warnings—to errors:

borg_exit_codes:
    - code: 100
      treat_as: error

The following configuration does that and treats Borg's backup file not found (exit code 107) as a warning:

borg_exit_codes:
    - code: 100
      treat_as: error
    - code: 107
      treat_as: warning

If you don't know the exit code for a particular Borg error or warning you're experiencing, you can usually find it in your borgmatic output when --verbosity 2 is enabled. For instance, here's a snippet of that output when a backup file is not found:

/noexist: stat: [Errno 2] No such file or directory: '/noexist'
...
terminating with warning status, rc 107

So if you want to configure borgmatic to treat this as an warning instead of an error, the exit status to use is 107.

With Borg version 1.2 and earlier Older versions of Borg didn't support granular exit codes, but still distinguished between Borg errors and warnings. For instance, to elevate Borg warnings to errors, thereby causing borgmatic to error on them, use the following borgmatic configuration with Borg 1.2 or below:

borg_exit_codes:
    - code: 1
      treat_as: error

Be aware though that Borg exits with a warning code for a variety of benign situations such as files changing while they're being read, so this example may not meet your needs. Upgrading to Borg 1.4+ is recommended.