travis: use cabal-install 3.0.

Author: quasicomputational

.travis.yml

@@ -1,4 +1,4 @@
 # ++++++++++++++++++++ WARNING ++++++++++++++++++++
 # This file is generated by 'meta generate'. Don't hand-edit.
 # ++++++++++++++++++++ WARNING ++++++++++++++++++++
-{"sudo":false,"language":"generic","branches":{"only":["staging","trying"]},"notifications":{"email":false},"cache":{"directories":["$HOME/.cabal/store","$HOME/.cabal/bin"]},"matrix":{"fast_finish":true,"allow_failures":[{"env":"PROJECT=ghc-8.8"},{"env":"PROJECT=ghc-head"}]},"jobs":{"include":[{"env":"PROJECT=ghc-8.6","addons":{"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.6.5","cabal-install-2.4"]}},"before_install":["export PATH=/opt/ghc/bin:$PATH"],"install":"./travis/deps.sh","script":["./travis/build.sh","./travis/meta.sh"]},{"env":"PROJECT=ghc-8.8","addons":{"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.8.1","cabal-install-3.0"]}},"before_install":["export PATH=/opt/ghc/bin:$PATH"],"install":"./travis/deps.sh","script":["./travis/build.sh"]},{"env":"PROJECT=ghc-head","addons":{"apt":{"sources":["hvr-ghc"],"packages":["ghc-head","cabal-install-head"]}},"before_install":["export PATH=/opt/ghc/bin:$PATH"],"install":"./travis/deps.sh","script":["./travis/build.sh"]},{"env":"PROJECT=ghc-8.4","addons":{"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.4.4","cabal-install-2.4"]}},"before_install":["export PATH=/opt/ghc/bin:$PATH"],"install":"./travis/deps.sh","script":["./travis/build.sh"]}]}}
+{"sudo":false,"language":"generic","branches":{"only":["staging","trying"]},"notifications":{"email":false},"cache":{"directories":["$HOME/.cabal/store","$HOME/.cabal/bin"]},"matrix":{"fast_finish":true,"allow_failures":[{"env":"PROJECT=ghc-8.8"},{"env":"PROJECT=ghc-head"}]},"jobs":{"include":[{"env":"PROJECT=ghc-8.6","addons":{"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.6.5","cabal-install-3.0"]}},"before_install":["export PATH=/opt/ghc/bin:$PATH"],"install":"./travis/deps.sh","script":["./travis/build.sh","./travis/meta.sh"]},{"env":"PROJECT=ghc-8.8","addons":{"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.8.1","cabal-install-3.0"]}},"before_install":["export PATH=/opt/ghc/bin:$PATH"],"install":"./travis/deps.sh","script":["./travis/build.sh"]},{"env":"PROJECT=ghc-head","addons":{"apt":{"sources":["hvr-ghc"],"packages":["ghc-head","cabal-install-head"]}},"before_install":["export PATH=/opt/ghc/bin:$PATH"],"install":"./travis/deps.sh","script":["./travis/build.sh"]},{"env":"PROJECT=ghc-8.4","addons":{"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.4.4","cabal-install-3.0"]}},"before_install":["export PATH=/opt/ghc/bin:$PATH"],"install":"./travis/deps.sh","script":["./travis/build.sh"]}]}}

packages/meta/src/Q4C12/Meta.hs

@@ -273,7 +273,7 @@ travisConfiguration buildMap = Aeson.Encoding.pairs $ fold
         , Aeson.Encoding.pair "packages" $ Aeson.Encoding.list Aeson.Encoding.text
           [ "ghc-" <> ghcAptVersion ghc
           , case ghcRegularity ghc of
-              Regular{} -> "cabal-install-2.4"
+              Regular{} -> "cabal-install-3.0"
               PreRelease ver _ -> "cabal-install-" <> ver
           ]
         ]