GHC 9.4+ hangs indefinitely when compiling the monus-weighted-search package

Summary

GHC 9.4+ hangs indefinitely when compiling the Control.Monad.Heap module in the monus-weighted-search package. The hang seems to happen in the Constructed Product Result analysis.

Steps to reproduce

1. git clone https://github.com/oisdk/monus-weighted-search.git
2. cd monus-weighted-search
3. Observe the following terminates: cabal build -w ghc-9.2.8 lib:monus-weighted-search
4. Observe the following hangs indefinitely: cabal build -w ghc-9.4.1 lib:monus-weighted-search

Additional diagnostic steps that confirm the issue location:

1. Update monus-weighted-search.cabal so the ghc-options includes -v
2. Observe cabal build -w ghc-9.4.1 lib:monus-weighted-search gets stuck in the Constructed Product Result analysis

   
        *** Simplifier [Control.Monad.Heap]:
        Result size of Simplifier iteration=1
          = {terms: 10,731, types: 40,759, coercions: 17,664, joins: 12/491}
        Result size of Simplifier iteration=2
          = {terms: 10,711, types: 40,727, coercions: 16,669, joins: 12/487}
        Result size of Simplifier
          = {terms: 10,711, types: 40,727, coercions: 16,669, joins: 12/487}
        !!! Simplifier [Control.Monad.Heap]: finished in 106.51 milliseconds, allocated 182.290 megabytes
        *** Demand analysis [Control.Monad.Heap]:
        Result size of Demand analysis
          = {terms: 10,711, types: 40,727, coercions: 16,669, joins: 12/487}
        !!! Demand analysis [Control.Monad.Heap]: finished in 19.83 milliseconds, allocated 32.152 megabytes
        *** Constructed Product Result analysis [Control.Monad.Heap]:
        

3. Update monus-weighted-search.cabal so the ghc-options includes -fno-strictness
4. Observe cabal build -w ghc-9.4.1 lib:monus-weighted-search terminates

Expected behavior

GHC should successfully compile the package. Alternatively, if there is an issue with the code, GHC should report an error rather than hang indefinitely.

Environment

• GHC version used: 9.4.1, 9.4.2, 9.4.4, 9.4.8, 9.6.6, 9.10.1 (confirmed hanging in all these versions), 9.2.8 (confirmed terminating)
• Operating System: macOS 15.3.2
• System Architecture: arm64