Reader macro conflict on Allegro CL

[adlai]

On a Travis CI worker running Allegro CL 9.0 [Linux (x86)], (use-syntax :annot) triggers Reader macro conflict while trying to merge the dispatch macro characters #\# #\U from #<readtable named CL-ANNOT.SYNTAX> into #<readtable>.

Reproduced in Scalpl's Job #7.2, which seems to occur when CL-DBI compilation reaches this call to use-syntax.