Splitting make -j across configs (jobs // nconfigs) made each parallel
config single-threaded on a 4-vCPU VM, so 3 concurrent serial builds
were as slow as the old sequential path (~7min). Windows (MSBuild)
runs the 3 configs in parallel each using all cores and finishes in
~2min on the same vCPU/RAM. Mirror that: give every parallel config
the full make -j; the scheduler absorbs the mild oversubscription.
Simone
4b4c7b5975