* Paul Wise <pabs@debian.org>, 2016-04-27, 18:47:
And for stretch, there's "dpkg-buildpackage -Jauto" (not to be confused with -jauto, which is evil).-jauto replaces auto with the number of processors. Why is that evil? What does -Jauto do?
"dpkg-buildpackage -J..." sets DEB_BUILD_OPTIONS=parallel=N."dpkg-buildpackage -j..." sets DEB_BUILD_OPTIONS=parallel=N and puts -jN into MAKEFLAGS; the latter imposes parallelism on packages that weren't designed for it.
-- Jakub Wilk