The work-in-progress was using a source tree of libmypaint embedded into GIMP tree. This is a cleaning with pkg-config test in configure, and correct includes.
77b0455 app: clean compilation with external libmypaint.
app/Makefile.am | 2 +-
app/paint/Makefile.am | 41 ++---------------------------------------
app/paint/gimpmybrush.c | 6 +++---
configure.ac | 15 +++++----------
4 files changed, 11 insertions(+), 53 deletions(-)
Upstream: git.gnome.org