Building with this command (after https://github.com/10gen/mongo/pull/16453):

python buildscripts/scons.py --build-profile=fast --ninja=disabled -j200 --variables-files=etc/scons/scons_experimental_scheduler.vars BAZEL_BUILD_ENABLED=1 BAZEL_INTEGRATION_DEBUG=1 prove-unittests

We see an error message from the way libunwind is built:

ld.lld: error: build/fast/third_party/unwind/libunwind.so: undefined reference to _Uaarch64_getcontext_trace [--no-allow-shlib-undefined]
clang-12: error: linker command failed with exit code 1 (use -v to see invocation)

This ticket should also update the evergreen tasks to build something more substantial to flesh out any similar errors before they are merged.