If you have problems with GNU M4 or think you’ve found a bug, please report it. Before reporting a bug, make sure you’ve actually found a real bug. Carefully reread the documentation and see if it really says you can do what you’re trying to do. If it’s not clear whether you should be able to do something or not, report that too; it’s a bug in the documentation!
Before reporting a bug or trying to fix it yourself, try to isolate it
to the smallest possible input file that reproduces the problem. Then
send us the input file and the exact results
m4 gave you. Also
say what you expected to occur; this will help us decide whether the
problem was really in the documentation.
Once you’ve got a precise problem, send e-mail to
firstname.lastname@example.org. Please include the version number of
you are using. You can get this information with the command
m4 --version. Also provide details about the platform you are
Non-bug suggestions are always welcome as well. If you have questions about things that are unclear in the documentation or are just obscure features, please report them too.