[GHC] #16066: internal error: PAP object entered!

[GHC]

#16066: internal error: PAP object entered!
----------------------------------------+----------------------------------
           Reporter:  dnspies           |             Owner:  (none)
               Type:  bug               |            Status:  new
           Priority:  normal            |         Milestone:
          Component:  Compiler          |           Version:  8.4.4
           Keywords:                    |  Operating System:  iOS
       Architecture:  Unknown/Multiple  |   Type of failure:  Runtime crash
          Test Case:                    |        Blocked By:
           Blocking:                    |   Related Tickets:
Differential Rev(s):                    |         Wiki Page:
----------------------------------------+----------------------------------
 While trying to debug why my test didn't seem to be running, I got an
 internal error (below).

 After a clean and rebuild it happened again so it's not a flake.
 Unfortunately I don't know what's causing it so I can't produce an MWE,
 but I can link to the project and commit on GitHub:

 https://github.com/dspies-
 leapyear/persistwrap/tree/885a079923cb3eefb24db344f5e2fddee9fab425

 Just run the test with:

 {{{
 stack test persistwrap:persistwrap-test
 }}}

 {{{
 Progress 9/10: persistwrap-0.1.0.0test/Driver.hs
   test_widget_schemas:                 persistwrap-test: internal error:
 PAP object entered!
     (GHC version 8.4.4 for x86_64_apple_darwin)
     Please report this as a GHC bug:
 http://www.haskell.org/ghc/reportabug
 persistwrap-test: SignalException 6

 persistwrap-0.1.0.0: Test suite persistwrap-test failed
 Completed 10 action(s).
 Test suite failure for package persistwrap-0.1.0.0
     persistwrap-test:  exited with: ExitFailure (-6)
 Logs printed to console
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16066>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler