nofib is not working

When I try to run nofib, I get this

Command line: /home/simonpj/code/HEAD/nofib/../_build/stage1/bin/ghc -Rghc-timing -c real/ben-raytrace/SamplerMonad/Naive.hs -w -i_make/2025-03-14/real/ben-raytrace -odir=_make/2025-03-14/real/ben-raytrace -hidir=_make/2025-03-14/real/ben-raytrace -o _make/2025-03-14/real/ben-raytrace/SamplerMonad/Naive.o -O2 -Wno-tabs -package-env - -package binary -package bytestring -package array -package parallel -package primitive -package transformers -package mtl -package ghc-prim -package random -package-db _make/2025-03-14/dep-packages/ghc-9.13.20250312/package.db -no-user-package-db +RTS --machine-readable -t_make/2025-03-14/real/ben-raytrace/SamplerMonad/Naive.o.stats
Exit code: 1
Stderr:
real/ben-raytrace/SamplerMonad/Naive.hs:32:10: error: [GHC-18872]
    • Couldn't match type ‘MutableGen f0 (SamplerM s)’ with ‘Gen’
        arising from a use of ‘System.Random.Internal.$dmuniformByteArrayM’
      The type variable ‘f0’ is ambiguous
    • In the expression:
        System.Random.Internal.$dmuniformByteArrayM @Gen @(SamplerM s)
      In an equation for ‘uniformByteArrayM’:
          uniformByteArrayM
            = System.Random.Internal.$dmuniformByteArrayM @Gen @(SamplerM s)
      In the instance declaration for ‘StatefulGen Gen (SamplerM s)’
    • Relevant bindings include
        uniformByteArrayM :: Bool
                             -> Int -> Gen -> SamplerM s Data.Array.Byte.ByteArray
          (bound at real/ben-raytrace/SamplerMonad/Naive.hs:32:10)
   |
32 | instance StatefulGen Gen (SamplerM s) where
   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

What's up? It's very disabling.

Here's my command line

cabal v2-run  --allow-newer -- nofib-run --compiler=`pwd`/../_build/stage1/bin/ghc --output=`date -I`