Add MAKE_JOBS_UNSAFE=yes to avoid this parallel build failure:
msgfmt: error while opening "trans/ak.mo" for writing: No such file or directory
gmake: * [Makefile:414: trans/ak.mo] Error 1
gmake: * Waiting for unfinished jobs....
...Preparing translation files...
30 warnings generated.
gmake: Leaving directory '/wrkdirs/usr/ports/games/tuxpaint/work/tuxpaint-0.9.22'
> Compilation failed unexpectedly.
Try to set MAKE_JOBS_UNSAFE=yes and rebuild before reporting the failure to