Have to delete a statement to get stack build to work

[jstr045329]

When I run stack repl, I get a build error in hdbc-postgresql/Database/HDBC/PostgreSQL/Connection.hsc line 60. The error message:

Database/HDBC/PostgreSQL/Connection.hsc:60:130: error:
lexical error in string/character literal at character 's'

That line is a statement similar to:
60: do "some error message"
61: return whateverExpression

The weird part is that the letter 's' is in the middle of "some error message".

I deleted the entire error message expression, so the resulting file is:

60: do -- rest of line is blank
61: return whateverExpression

$ stack clean
$ stack build --ghc-options=-fforce-recomp

and the package builds and I can do things like this:

λ> conn <- connectPostgreSQL "host=localhost dbname=whateverName user=username"

and it appears to work okay, but obviously deleting error messages is not a real fix.

Does anybody know what this is about?