stToPrim is only available since primitive-0.6.2.0

[phadej]

https://hackage.haskell.org/package/primitive-0.7.4.0/docs/Control-Monad-Primitive.html#v:stToPrim

% cabal build -w ghc-8.8.4 --constraint='primitive <0.7'
Resolving dependencies...
Build profile: -w ghc-8.8.4 -O1
In order, the following will be built (use -v for more details):
 - vector-algorithms-0.9.0.1 (lib) (first run)
Configuring library for vector-algorithms-0.9.0.1..
Preprocessing library for vector-algorithms-0.9.0.1..
Building library for vector-algorithms-0.9.0.1..
[ 1 of 11] Compiling Data.Vector.Algorithms.Common ( src/Data/Vector/Algorithms/Common.hs, /codetmp/vector-algorithms-0.9.0.1/dist-newstyle/build/x86_64-linux/ghc-8.8.4/vector-algorithms-0.9.0.1/build/Data/Vector/Algorithms/Common.o )

src/Data/Vector/Algorithms/Common.hs:124:27: error:
    Variable not in scope: stToPrim :: m0 () -> m ()
    |
124 | copyToSmaller !dst !src = stToPrim $ do_copy 0
    |                           ^^^^^^^^

[phadej]

I made a revision: https://hackage.haskell.org/package/vector-algorithms-0.9.0.1/revisions/