I have this symlinked into ~/bin, when looking at the help/usage
it would previously print the fully qualified path to the script
making the help very difficult to read.
Running the tests will be moved to a separate test command which can
then leverage the availability of different targets and run either unit
tests on the host or the image in QEMU in self-test mode. :^)
- Only call ensure_toolchain for non-lagom targets
- Use host addr2line, we can't expect the i686 toolchain's addr2line to
support the host's binary executable format
- Don't export SERENITY_ARCH and TOOLCHAIN_DIR, don't need them anymore
