tag deletion by regexp very slow
In the GCC repository conversion, I see the "tag /emptycommit/ delete" command take about seven hours, i.e. the vast bulk of the time spent on the conversion is running that single reposurgeon command (which deletes over 4000 tags). You can see the same problem earlier in the GCC conversion with the deletion of /-root$/ tags (half an hour with my latest proposed changes to gcc.lift, a bit less when /branch-root|branchpoint/ have been deleted first).