Please report bugs to the bug tracker at Savannah. You may also email bug reports to the libmu-bug@nongnu.org mailing list. See also the list information page for libmu-bug. Include enough information to reproduce the bug if possible, as well as the version of Mu, your machine architecture, operating system, etc. Make sure to read the documentation for the functions you are using, and ensure that you are using the functions correctly. You should also include any error messages if applicable, and a backtrace if you can. If possible, include a source file (preferably minimal) that causes the bug to occur.
If you are reporting a test failure (run by make check), include
the file tests/testsuite.log in your report. Even if you’re not
reporting a test failure, it can still be helpful to run make
check and include tests/testsuite.log.
For more information on writing effective bug reports, I suggest reading Simon Tatham’s excellent essay, How to Report Bugs Effectively
You can also send reports for bugs in this manual itself to the bug tracker or mailing list.