kunit kernel build could fail if there are ny build artifacts from a
prior kernel build. These can be hard to debug if the build artifact
happens to be generated header file. It took me a while to debug kunit
build fail on ARCH=x86_64 in a tree which had a generated header file
arch/x86/realmode/rm/pasyms.h

make ARCH=um mrproper will not clean the tree. It is necessary to run
make ARCH=x86_64 mrproper

Example work-flow that could lead to this:

        make allmodconfig (x86_64)
        make
        ./tools/testing/kunit/kunit.py run

Add this to the documentation and kunit.py build help message.

Shuah Khan (2):
  doc: kunit: add information about cleaning source trees
  kunit: add tips to clean source tree to build help message

 Documentation/dev-tools/kunit/start.rst | 12 ++++++++++++
 tools/testing/kunit/kunit.py            |  2 +-
 2 files changed, 13 insertions(+), 1 deletion(-)

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2.47.2