This source package builds native packages and packages targeting
debian architectures.  To shorten a test build, some of these builds
can be skipped.

DEB_BUILD_OPTIONS="parallel=<N> <option> ..." dpkg-buildpackage ...

Where <option> can be:

 - nomult to disable the binutils-multilib build
 - nohppa to disable the hppa64 build
 - nopgo to disable the PGO/LTO build
 - nocheck to disable running the testsuite
 - nocross to disable all builds for other targets

To build only a subset of the target architectures, also
set CROSS_ARCHS in the env, e.g. CROSS_ARCHS="arm64 ppc64el"