This script shows an error with the
persistent-postgresql Haskell library.
It reliably crashes with this output:
libpq-error: libpq: failed (another command is already in progress)
As far as I can tell this only affects PostgreSQL while using a pool.
withPostgresqlPool is changed to
withPostgresqlConn, this error does not happen.
async appears to make this problem go away.
I cannot reproduce this problem using
I don't get the error if I use
rawSql instead of