[development] Debugging updates

Does anyone have ideas for ways to debug update functions in the install file figure out what's going on when they don't work as expected or when I get reports of problems? Is there any way to see the query logs that the devel module creates from within updates? If I use update_sql() I can tell what queries ran, but there are times when I need to use db_query() instead and I can get no clue to what is going on when that runs. And I can't find any way to display messages back to myself or see results of print_r() or any of the other things I do elsewhere to debug scripts. I've tried to execute the update() script directly from within a normal page, but that won't work either. Ideas welcome! Karen