I ran top and tried to renice the running emerge command. as I suspected, the child processes stayed "nice" I wanted them to be mean dang it! and I didn't want to have to restart the emerge because I was so long into it.... I could just renice everything else on the system to the same level of niceness... but that's getting silly.
IMO this is way beyond the scope of portage, shuold rather be a separate tool that can renices any process tree.
I tried using the separate tool !! top could not renice it.... emerge spawns new processes at a nice level specified in make.conf I suggest that portage checks it's own nice level, and spans new processes at it's own level rather than some configuration value. We would then be ABLE to renice portage.
Ah, your inital comment didn't make it clear you were talking about new subprocesses.
ok... I thought it was obvious and I see how it's not. And I agree that it would be way beyond the scope to catch keyclicks or whatever to renice it...
Took another look at it today, and AFAICT it works as it should.