I know, that pprace 0.5 is only alpha, but it's enough stable to include it.
I have tried to modify the 0.3.1 ebuild, but 'ebuild ... digest' doesn't want to create manifest file, because the ebuild's name should be: ppracer-0.5alpha.ebuild, but the 'alpha' word can't be included because of:
!!! games-arcade/ppracer-0.5alpha does not follow correct package syntax.
*** This bug has been marked as a duplicate of 107358 ***