Both amule ebuilds in the tree force MAKEOPTS=-j1 (line 107), but both of them compile well without that, so please remove. Also, the ebuilds filter some flags (line 105) because of bug #74457, closed long time ago. Is related to hardened, so I can't test it, but my guess is that the filtering is useless too. Reproducible: Always
Done on 2.2.3