Before executing the qmerge: 6.3G ./dev-lang/rust-1.29.1-r1 We need to add CHECKREQS_DISK_BUILD="7G"
https://github.com/gentoo/gentoo/pull/10448
That's a bit pessimistic. It might be use-flag dependant, but even with xFLAGS="-Og -g" on amd64 I get * Final size of build directory: 5415076 KiB ( 5.1 GiB)
I'm using xFLAGS="-O2 -pipe -march=broadwell" (I think that's pretty much the default)
Thanks for the PR! I'm going with a slightly more targeted fix, and without bumping the revision (which doesn't help in this case). *** This bug has been marked as a duplicate of bug 626742 ***