Can't build master (Expected kind ‘k0 -> k0 -> k1’, but ‘(:~~:)’ has kind ‘*’)

Trying to build the master branch using commit 34d75688 yields the following error:

"inplace/bin/ghc-stage1" -hisuf hi -osuf  o -hcsuf hc -static  -O0 -H64m -Wall      -this-unit-id base-4.15.0.0 -hide-all-packages -i -ilibraries/base/. -ilibraries/base/dist-install/build -Ilibraries/base/dist-install/build -ilibraries/base/dist-install/build/./autogen -Ilibraries/base/dist-install/build/./autogen -Ilibraries/base/include -Ilibraries/base/dist-install/build/include    -optP-include -optPlibraries/base/dist-install/build/./autogen/cabal_macros.h -package-id ghc-bignum-1.0 -package-id ghc-prim-0.7.0 -package-id rts -this-unit-id base -Wcompat -Wnoncanonical-monad-instances -XHaskell2010 -O  -no-user-package-db -rtsopts  -Wno-trustworthy-safe -Wno-deprecated-flags     -Wnoncanonical-monad-instances  -outputdir libraries/base/dist-install/build  -dynamic-too -c libraries/base/./Data/Type/Equality.hs -o libraries/base/dist-install/build/Data/Type/Equality.o -dyno libraries/base/dist-install/build/Data/Type/Equality.dyn_o

libraries/base/Data/Type/Equality.hs:125:13: error:
    • Expected kind ‘k0 -> k0 -> k1’, but ‘(:~~:)’ has kind ‘*’
    • In the type ‘a :~~: a’
      In the definition of data constructor ‘HRefl’
      In the data declaration for ‘:~~:’
    |
125 |    HRefl :: a :~~: a
    |             ^^^^^^^^