I do have at my tinderbox : MAKEOPTS="-j 1" NINJAFLAGS="-j 1" EGO_BUILD_FLAGS="-p 1" GOMAXPROCS="1" GO19CONCURRENTCOMPILATION=0 RUSTFLAGS="-C codegen-units=1" RUST_TEST_THREADS=1 RUST_TEST_TASKS=1 but the attached pstree shows that it is not respected
Created attachment 523010 [details] 20.20180308-191101 pstree
*** This bug has been marked as a duplicate of bug 893316 ***
sorry, not a dupe, I missed GOMAXPROCS=1. Still an issue?
It seems MAKEOPTS=-j1 is pretty effective these days but please reopen if you still observe an issue.