kbuild: strip sub_make_done from test-script environment

The exported sub_make_done variable leaks into the environment of all
child processes. When make targets like tcheck spawn independent
make-invocations with O=, those child-makes inherit sub_make_done=1,
skip the KBUILD_OUTPUT setup and try to build in the source tree.

A global 'unexport sub_make_done' cannot be used because the build
system itself re-invokes the top-level Makefile for syncconfig (via
'$(MAKE) -f $(srctree)/Makefile syncconfig'). Without sub_make_done,
that child make re-enters the KBUILD_OUTPUT block and recomputes
abs_objtree. With a relative O= path this resolves to a nested
directory (e.g. build/build/) where .config does not exist.

Instead, use 'env -u sub_make_done' in the test-target recipes so only
the test scripts see a clean environment. This allows their child make
invocations to process O= correctly without affecting internal kbuild
recursion.

This is not strictly a bugfix, but compare with:

commit 27529f1cb02d ("kbuild: skip parsing pre sub-make code for recursion")

Signed-off-by: Simon Glass <[email protected]>

0 files changed, 0 insertions, 0 deletions