Compiling chromium causes a very high load. I have seen it rise to 12 and above. Since I have only four (virtual) cores, it is not even possible to kill the build without a cold restart. I have worked around this in the past by compiling chromium separately using MAKEOPTS=-j1. But when trying to compile 15.0.865.0 this does not help anymore. It still climbed to 6 at which point I killed the build while I was still able to.
Yeah, compiling chromium requires resources. I'm not sure if we can do anything about it. Feel free to re-open with precise suggestions how we can improve the situation (forcing everyone to compile with -j1 is not an option) or with patches.