whilst ninja has -j2 portage spawns here 32 c++ processes at the tinderbox :-/ : │ └─ebuild.sh,6123 /usr/lib/portage/python3.8/ebuild.sh compile │ └─ninja,6489 -v -j2 -l0 │ ├─x86_64-pc-linux,6790 -I/var/tmp/portage/sci-libs/ignition-math-6.5.0/work/ignition-math6_6.5.0/include -Iinclude -I/var/tmp/portage/sci-libs/ignition-math-6.5.0/work/ignition-math6_6.5.0/test/gtest/include -I/var/tmp/portage/sci-libs/ignition-math-6.5.0/work/ignition-math6_6.5.0/test/gtest -I/var/tmp/portage/sci-libs/ignition-math-6.5.0/work/ignition-math6_6.5.0/test -pipe -march=native -fno-diagnostics-color -O2 -Wall -Wextra -Wno-long-long -Wno-unused-value -Wfloat-equal -Wshadow -Winit-self -Wswitch-default -Wmissing-include-dirs -pedantic -UNDEBUG -msse -msse2 -mfpmath=sse -msse3 -mssse3 -msse4.1 -msse4.2 -std=c++17 -MD -MT test/CMakeFiles/gtest.dir/gtest/src/gtest-all.cc.o -MF test/CMakeFiles/gtest.dir/gtest/src/gtest-all.cc.o.d -o test/CMakeFiles/gtest.dir/gtest/src/gtest-all.cc.o -c /var/tmp/portage/sci-libs/ignition-math-6.5.0/work/ignition-math6_6.5.0/test/gtest/src/gtest-all.cc │ │ ├─cc1plus,6842 -quiet -I /var/tmp/portage/sci-libs/ignition-math-6.5.0/work/ignition-math6_6.5.0/include -I include -I /var/tmp/portage/sci-libs/ignition-math-6.5.0/work/ignition ...
tinderbox@mr-fox ~ $ pstree -Ulnspu 20520 init(1)───sudo(26929)───bwrap.sh(26980)───bwrap(27139)───bwrap(27154)───entrypoint(27177)───entrypoint(20513)───emerge(20520)─┬─python3.8(3922)───python3.8(4043)───sandbox(5353,portage)───ebuild.sh(5387)───ebuild.sh(6123)───ninja(6489)─┬─x86_64-pc-linux(6790)─┬─cc1plus(6842) │ │ └─as(6873) │ └─sh(11363)───cmake(11398)───cmake(11491)───ninja(11583)─┬─c++(760)─┬─cc1plus(2610) │ │ └─as(5776) │ ├─c++(2466)─┬─cc1plus(4341) │ │ └─as(8915) │ ├─c++(3844)─┬─cc1plus(5476) │ │ └─as(8765) │ ├─c++(8541)───as(16000) │ ├─c++(10592)─┬─cc1plus(16380) │ │ └─as(17815) │ ....