Errors building gimp using https://wiki.gimp.org/wiki/Hacking:Building
The instructions for building gimp, on https://wiki.gimp.org/wiki/Hacking:Building specify for installing mypaint to use the following:
> git clone https://github.com/mypaint/mypaint-brushes.git > git clone https://github.com/mypaint/libmypaint.git
However, this installs libmypaint 2, which is in alpha, and currently unrecognized by the configure script. The configure script complains that it finds no libmypaint at all.
In order to get the last stable version, the following commands could be added, after cloning the repos of mypaint.
git fetch --all --tags --prune git checkout tags/v1.4.0