Bug reports

If you have input that results in a crash or wrong output, then this might be a bug.

Step 1: Known bugs

We may already know about your problem. Check our bug tracker for open and closed issues:

Nota: Please DO NOT add bug reports directly to the bug tracker. However, once an issue has been added to the tracker, feel free to add more information to that report.

You should also check whether the LilyPond syntax has changed for the version you use (see the Changes document). In most cases, input files using older syntax can be converted to the new syntax automatically with a script, see Updating files with convert-ly.

Step 2: Creating a bug report

If you have discovered a bug that is not listed in the bug tracker, please help us by creating a bug report.

Nota: We only accept reports in the form of Tiny examples. We have very limited resources, so any non-minimal example will be rejected. Almost every bug can be demonstrated in five input lines or less!

Here is an example of a good bug report:

% Accidentals should be printed for only the first note
% in a tie, but this version prints flats on both notes.
\version "2.10.1"

\relative c'' {
 bes1 ~
 bes1
}

Step 3: Sending a bug report

Send your bug report via e-mail to the ‘bug-lilypond’ mailing list.

We strongly recommend that you subscribe to this list before sending your report; see

for more information.

Without subscribing it may take much longer until your report gets handled because your e-mail must be approved first before it is distributed to the people on the mailing list.

Step 4: Wait for a response

Once your bug report has been sent to the list, our Bug Squad will examine it; they may ask you for more information. You will be notified when the report will be added to the bug tracker. Please allow up to 4 days, as we have a limited number of volunteers for this task.

Once a bug has been added to the tracker, you can comment it to add more information about it. In order to be automatically notified about any activity on the tracker issue, you may subscribe by clicking the envelope symbol next to the issue title.

Optional help: show the desired behavior

Once an issue has been added to the tracker, it can be very helpful if we can see the desired output. Feel free to add input code and/or images (possibly created with other tools) which demonstrate what you think it should look like!