First of all, many thanks to Oleg for taking on maintainership of postgresql-simple. Oleg, your new github fork of postgresql-simple - which is now the official source of this package - does not have issues enabled. Where is the right place to report issues? In particular, the library is not building for us on Windows with GHC 8.6.3. One of our devs has a guess that it's related to GHC bug #16057. In any case, we'd like to file an issue for postgresql-simple. https://ghc.haskell.org/trac/ghc/ticket/16057 The evidence that this GHC bug may be at play is that compilation hangs in Database.PostgreSQL.Simple.FromField, which uses some TH splices. That is the same behavior we are seeing for ofther packages that are hit by this GHC bug on Windows. Thanks, Yitz