Development happens on github and the preferred contribution method is by forking the repository and issuing a pull request. Alternatively, just sending a patch to luis@luispedro.org will work just as well.
If you don’t know git (or another distributed version control system), which is a fantastic tool in general, there are several good git and github tutorials. You can start with their official documentation.
If you want to work on the C++ code, you can read the chapter in the internals before you start. Also, read the principles declaration.
If you compile mahotas in debug mode, then it will run slower but perform a lot of runtime checks. This is controlled by the DEBUG environment variable.
There are two levels:
The Makefile that comes with the source helps you:
make clean
make debug
make test
will rebuild in debug mode and run all tests. When you are done testing, use the fast Make target to get the non-debug build:
make clean
make fast
Using make will not change your environment. The DEBUG variable is set internally only.
If you don’t know about it, check out ccache which is a great tool if you are developing in compiled languages (this is not specific to mahotas or even Python). It will allow you to quickly perform make clean; make debug and make clean; make fast so you never get your builds mixed up.