An easy example is adding
.spacemacs, then running
SPC f e R, and then observing all the added
*-theme packages in your
themes-megapack out of your
dotspacemacs-configuration-layers list, then doing
SPC f e R and even
SPC q r, all the
*-theme packages remain, and executing
package-autoremove reports "Nothing to autoremove".
How to I clean up all these orphaned packages?