Struggling with taxonomy import.
After stripping everything out, the conclusion is that taxonomy_save_term, by itself, without even the hooks to add extra data, is simply too slow, with a minimum of three database calls per term. (data, hierarchy, vocabulary)
Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 1048576 bytes) in /RCS/agaric/agaric-sites/scf/includes/bootstrap.inc on line 836
134,217,728
Increased to 256MB. It ran forever, then returned this: