Recursive loop in context simplification with GHC 7.10.1

[Joe Hendrix]

Hi,

I’m trying to migrate some code that compiles under GHC 7.8.4 to GHC 7.10.1.

It uses the comparison operator (<=) in TypeLits, and seems to get in a recursive loop  when simplifying contexts.

I’ve included part of the output from "-ddump-tc-trace” once it gets stuck in the loop below.

I’d appreciate any help on understanding what is happening.  If it’s useful I could try to extract a minimal example showing the error, but I thought I’d try to understand what’s happening first.

Thanks,
Joe

===
flatten/flat-cache hit
  GHC.TypeLits.<=? [1, n_abP7[sk]]
  s_aifJ[fuv:0]
  cobox_aifK
Following filled tyvar
  s_aifJ[fuv:0] = 1 GHC.TypeLits.<=? n_abP7[sk]
flattenTyVar1
  n_abP7[sk]
  GHC.TypeLits.Nat
flatten/flat-cache hit
  GHC.TypeLits.<=? [1, n_abP7[sk]]
  s_aifJ[fuv:0]
  cobox_aifK
Following filled tyvar
  s_aifJ[fuv:0] = 1 GHC.TypeLits.<=? n_abP7[sk]
flattenTyVar1
  n_abP7[sk]
  GHC.TypeLits.Nat
flatten/flat-cache hit
  GHC.TypeLits.<=? [1, n_abP7[sk]]
  s_aifJ[fuv:0]
  cobox_aifK
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