package "primitive" fails to install under msys2-i686 (Windows)

If you follow the instructions for a 32-bit installation at https://ghc.haskell.org/trac/ghc/wiki/Building/Preparation/Windows, installation of alex fails. Not sure if this is an issue with alex or with the environment. Transcript:

$ cabal install alex
Resolving dependencies...
Downloading primitive-0.5.4.0...
Configuring primitive-0.5.4.0...
Failed to install primitive-0.5.4.0
Build log ( C:\Users\Gintas\AppData\Roaming\cabal\logs\primitive-0.5.4.0.log ):
[1 of 1] Compiling Main             ( C:\Users\Gintas\Downloads\msys32\tmp\primitive-0.5.4.0-2404\primitive-0.5.4.0\dist\setup\setup.hs, C:\Users\Gintas\Downloads\msys32\tmp\primitive-0.5.4.0-2404\primitive-0.5.4.0\dist\setup\Main.o )
Linking C:\Users\Gintas\Downloads\msys32\tmp\primitive-0.5.4.0-2404\primitive-0.5.4.0\dist\setup\setup.exe ...
Configuring primitive-0.5.4.0...
setup-Simple-Cabal-1.18.1.3-i386-windows-ghc-7.8.3.exe: Missing dependency on
a foreign library:
* Missing (or bad) header file: primitive-memops.h
This problem can usually be solved by installing the system package that
provides this library (you may need the "-dev" version). If the library is
already installed but in a non-standard location then you can use the flags
--extra-include-dirs= and --extra-lib-dirs= to specify where it is.
If the header file does exist, it may contain errors that are caught by the C
compiler at the preprocessing stage. In this case you can re-run configure
with the verbosity flag -v3 to see the error messages.

The primitive-memops.h file seems to be part of "primitive" itself.

Passing in -v3 does not print anything interesting.

$ cabal --version
cabal-install version 1.20.0.3
using version 1.20.0.1 of the Cabal library

$ cabal get primitive && cd primitive-* && cabal configure && cabal build
Unpacking to primitive-0.5.4.0\
Resolving dependencies...
Configuring primitive-0.5.4.0...
Building primitive-0.5.4.0...
Preprocessing library primitive-0.5.4.0...
[ 1 of 10] Compiling Data.Primitive.Internal.Compat ( Data\Primitive\Internal\Compat.hs, dist\build\Data\Primitive\Internal\Compat.o )
[ 2 of 10] Compiling Data.Primitive.MachDeps ( Data\Primitive\MachDeps.hs, dist\build\Data\Primitive\MachDeps.o )
[ 3 of 10] Compiling Data.Primitive.Internal.Operations ( Data\Primitive\Internal\Operations.hs, dist\build\Data\Primitive\Internal\Operations.o )
[ 4 of 10] Compiling Control.Monad.Primitive ( Control\Monad\Primitive.hs, dist\build\Control\Monad\Primitive.o )
[ 5 of 10] Compiling Data.Primitive.Types ( Data\Primitive\Types.hs, dist\build\Data\Primitive\Types.o )
[ 6 of 10] Compiling Data.Primitive.Array ( Data\Primitive\Array.hs, dist\build\Data\Primitive\Array.o )

Data\Primitive\Array.hs:32:1: Warning:
    The import of `Control.Monad.ST' is redundant
      except perhaps to import instances from `Control.Monad.ST'
    To import instances alone, use: import Control.Monad.ST()
[ 7 of 10] Compiling Data.Primitive.ByteArray ( Data\Primitive\ByteArray.hs, dist\build\Data\Primitive\ByteArray.o )
[ 8 of 10] Compiling Data.Primitive.Addr ( Data\Primitive\Addr.hs, dist\build\Data\Primitive\Addr.o )
[ 9 of 10] Compiling Data.Primitive   ( Data\Primitive.hs, dist\build\Data\Primitive.o )
[10 of 10] Compiling Data.Primitive.MutVar ( Data\Primitive\MutVar.hs, dist\build\Data\Primitive\MutVar.o )
In-place registering primitive-0.5.4.0...

Any idea what's missing here?