Comment 7 for bug 1713348

I manually un-installed kernel 4.13.0-rc2-doug2 and then re-installed it. No problem.
I used the rm-kernels-server script (from askubuntu.com) to un-install 4.13.0-rc2-doug2 and then re-installed it. No Problem.

I re-installed an older kernel, 4.10.0-rc7-chen. Still no problem with linux-purge. However, it does show on this:

$ dpkg-query -W -f='${db:Status-Abbrev} ${Package}\n' linux-'*' | grep "^un" | grep linux-modules
un linux-modules-4.10.0-rc7-chen
un linux-modules-4.10.0-stock
un linux-modules-4.5.0-stock
un linux-modules-4.8.0-stock
un linux-modules-4.9.0-stock

So, I guess the modules list thing was a red herring. I do not know why linux-purge wants to remove those extra 4 kernels that I did not ask it to remove.