Depend on the exact version of the in-tree Cabal library

e664431f · Andrey Mokhov · f8bd7949 · e664431f
Commit e664431f authored Mar 16, 2017 by Andrey Mokhov
--- a/hadrian.cabal
+++ b/hadrian.cabal
@@ -117,7 +117,7 @@ executable hadrian
                       , ScopedTypeVariables
    build-depends:       base >= 4.8 && < 5
                       , ansi-terminal        == 0.6.*
-                       , Cabal                == 1.25.*
+                       , Cabal                == 2.0.0.0
                       , containers           == 0.5.*
                       , directory            == 1.2.*
                       , extra                >= 1.4.7