Thanks for the tips Geraldo, but with an effort to avoid anything that might be forgotten or is more difficult to undo, I've been building my kernel the debian suggested method of "make deb-pkg" (with -j4 added to speed it up) in /usr/src/linux-5.11.9/, and something like "dpkg -i ../linux-image-5.11.9_5.11.9_amd64.deb". The "make -j4 deb-pkg" command runs "make clean" first, every time. To make matters even worse, my boot partition is too small to hold more than 4 modern kernels, so I "apt-get remove linux-image-5.11.9" each time before building the next test. Each build takes about two hours... :) I'm not complaining, though. I'm just trying to explain why I have been doing it this way. I'm sure you're right, though, that your commands would be spiffy. ;)