Panic when trying to openFile with -fdefer-type-errors

~ ✔︎ ghci
GHCi, version 8.4.4: http://www.haskell.org/ghc/  :? for help
Loaded GHCi configuration from /Users/vl200/.ghci
Prelude> :set -fdefer-type-errors 
Prelude> import System.IO
Prelude System.IO> openFile ".granule" ReadWriteMode 
ghc: panic! (the 'impossible' happened)
  (GHC version 8.4.4 for x86_64-apple-darwin):
	nameModule
  system $dShow_a1QU
  Call stack:
      CallStack (from HasCallStack):
        callStackDoc, called at compiler/utils/Outputable.hs:1150:37 in ghc:Outputable
        pprPanic, called at compiler/basicTypes/Name.hs:241:3 in ghc:Name

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

But works fine when I don't :set that option.

~ ✔︎ ghci
GHCi, version 8.4.4: http://www.haskell.org/ghc/  :? for help
Loaded GHCi configuration from /Users/vl200/.ghci
Prelude> import System.IO
Prelude System.IO> openFile ".granule" ReadWriteMode 
{handle: .granule}
Prelude System.IO> 

changed weight to 5

added GHCi Tbug Trac import labels

Also getting this with 8.4.4 and independent of Stack

~ ✔︎ ghci
GHCi, version 8.4.4: http://www.haskell.org/ghc/  :? for help
Loaded GHCi configuration from /Users/vl200/.ghci
Prelude> import System.IO
Prelude System.IO> openFile ".granule" ReadWriteMode 
ghc: panic! (the 'impossible' happened)
  (GHC version 8.4.4 for x86_64-apple-darwin):
	nameModule
  system $dShow_a1QU
  Call stack:
      CallStack (from HasCallStack):
        callStackDoc, called at compiler/utils/Outputable.hs:1150:37 in ghc:Outputable
        pprPanic, called at compiler/basicTypes/Name.hs:241:3 in ghc:Name

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

Prelude System.IO> 

changed title from Panic when trying to openFile to Panic when trying to openFile with -fdefer-type-errors

changed the description

Trac metadata

Trac field	Value
Version	8.4.3 → 8.4.4

closed

Thanks for the bug report. This is a duplicate of #14963 (closed), so closing. It's worth noting that this issue no longer occurs in GHC 8.6.

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedDuplicate
Related	- → #14963 (closed)

added runtime crash label

added Pnormal label