jobs safety of gcc8 package

[David Holland <dholland-pkgtech%netbsd.org@localhost>]

Yesterday I was building gcc8 so I could update my fortran stuff, and
with MAKE_JOBS set to 6 it failed, the symptoms being first doing two
concurrent ar updates of libbackend.a and then shortly after crashing
out because libbackend.a was corrupted. Restarting the build at this
point after deleting all files namedlibbackend.a repeated the problem
consistently (tried several times). After restarting with 1 job the
build (eventualy) completed.

Should we tag it not MAKE_JOBS_SAFE? Does anyone have data about how
many jobs it can handle? (And did anyone ever implement per-package
jobs limits?)

-- 
David A. Holland
dholland%netbsd.org@localhost