travis: Install Cabal library before anything else.
I'm hoping this fixes the issue with travis
builds with earlier ghc versions.
See https://github.com/haskell/cabal/issues/4456
commit6b43a01a3c732c16d5e5cc22420512da7ecf7989
authorJohn MacFarlane <jgm@berkeley.edu>
dateThu 28 Jun 2018, 12:41 (8 years ago)
parent4a712b4
.travis.yml+1
@@ -117,6 +117,7 @@ install:
117117 cabal)
118118 cabal --version
119119 travis_retry cabal update
120+ cabal install Cabal
120121 cabal install --disable-optimization --only-dependencies --flags="$FLAGS" --enable-tests --force-reinstalls --reorder-goals --max-backjumps=-1 $CABALARGS
121122 ;;
122123 esac