Warning: The install command is a part of the legacy v1 style of cabal usage.

Please switch to using either the new project style and the new-install
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Resolving dependencies...
Starting     grid-7.8.10
Building     grid-7.8.10
Completed    grid-7.8.10
Starting     som-10.1.0
Building     som-10.1.0
Failed to install som-10.1.0
Build log ( /home/builder/.cabal/logs/ghc-8.6.1/som-10.1.0-KEdmTzJushkHYFld6J9wri.log ):
cabal: Entering directory '/tmp/cabal-tmp-7549/som-10.1.0'
Configuring som-10.1.0...
Preprocessing library for som-10.1.0..
Building library for som-10.1.0..
[ 1 of 11] Compiling Data.Datamining.Clustering.Classifier ( src/Data/Datamining/Clustering/Classifier.hs, dist/build/Data/Datamining/Clustering/Classifier.o )
[ 2 of 11] Compiling Data.Datamining.Clustering.DSOMInternal ( src/Data/Datamining/Clustering/DSOMInternal.hs, dist/build/Data/Datamining/Clustering/DSOMInternal.o )

src/Data/Datamining/Clustering/DSOMInternal.hs:83:3: error:
    • Illegal nested constraint ‘G.FiniteGrid (GM.BaseGrid gm p)’
      (Use UndecidableInstances to permit this)
    • In the instance declaration for ‘GM.GridMap (DSOM gm x k) p’
   |
83 |   (F.Foldable gm, GM.GridMap gm p, G.FiniteGrid (GM.BaseGrid gm p)) =>
   |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^...
cabal: Leaving directory '/tmp/cabal-tmp-7549/som-10.1.0'
cabal: Error: some packages failed to install:
som-10.1.0-KEdmTzJushkHYFld6J9wri failed during the building phase. The
exception was:
ExitFailure 1