[This](https://gitlab.haskell.org/ghc/head.hackage/-/pipelines/108736) head.hackage nightly pipeline failed to build `pqueue` with the following error: ``` Renamer/typechecker [Data.PQueue.Prio.Min]: alloc=25102384 time=21.742 src/Data/PQueue/Prio/Min.hs:35:3: error: [GHC-88993] • The type constructor ‘MinPQueue’ is not the parent of the data constructor ‘Empty’. Data constructors can only be exported with their parent type constructor. Parent: MinPQueue • In the export: MinPQueue(Data.PQueue.Prio.Min.Empty, (:<)) | 35 | MinPQueue (Data.PQueue.Prio.Min.Empty, (:<)), | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [12 of 13] Compiling Data.PQueue.Min ( src/Data/PQueue/Min.hs, dist/build/Data/PQueue/Min.o, dist/build/Data/PQueue/Min.dyn_o ) *** Parser [Data.PQueue.Min]: Parser [Data.PQueue.Min]: alloc=6808592 time=2.564 *** Renamer/typechecker [Data.PQueue.Min]: *** ConsistencyCheck [Data.PQueue.Min]: ConsistencyCheck [Data.PQueue.Min]: alloc=46024 time=0.072 Renamer/typechecker [Data.PQueue.Min]: alloc=16820256 time=14.244 src/Data/PQueue/Min.hs:32:3: error: [GHC-88993] • The type constructor ‘MinQueue’ is not the parent of the data constructor ‘Empty’. Data constructors can only be exported with their parent type constructor. Parent: MinQueue • In the export: MinQueue(Data.PQueue.Min.Empty, (:<)) | 32 | MinQueue (Data.PQueue.Min.Empty, (:<)), | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Error: [Cabal-7125] Failed to build pqueue-1.5.0.0 (which is required by test-Agda-1.0). See the build log above for details. ``` It looks like there has been a regression in the handling of this parent of data constructor check. Perhaps this is related to https://gitlab.haskell.org/ghc/ghc/-/commit/bdf93da8cf8d92399e7a53a5cc3455bf15673876 (cc @sheaf) This is the module that fails to compile: https://github.com/lspitzner/pqueue/blob/master/src/Data/PQueue/Min.hs