Ok, I fixed the problem on my system but it looks like I found something missed in the
kernel source packages.
Here is the issue:
20210527 installs kernel 5.12.4-2 with
/usr/lib/modules/5.12.4-2-default/build as a symlink to
That symlink is bad and should be to
Since it was a new kernel install, it seems to me that it would not be a UsrMerge bug and
instead would be a bug in the kernel-source package.
After recreating the correct symlink using
ln -s ../../../../usr/src/linux-5.12.4-2-obj/x86_64/default build
vmware player 16.1.1 was then able to recompile the vmware kernel modules successfully.
I checked the prior kernel source symlink in /usr/lib/modules/5.12.4-1-default/build and
found that it too was wrong so that appears to be something that the UsrMerge migration
Please let me know if you need any other information.