I can't say for sure, sorry. Given the error comes from PostgreSQL (IntegrityError), I'd wager it's probably a PostgreSQL thing.
- [web2py] migration fails when modifying field with notnull=T... Alex
- [web2py] Re: migration fails when modifying field with ... Mathew Grabau
- [web2py] Re: migration fails when modifying field w... Alex
- [web2py] Re: migration fails when modifying fie... Mathew Grabau