coala-bears.cabal: Create and use

coala has three haskell dependencies:

- ghc-mod 5.6.0.0
- hlint 1.9.26
- ShellCheck 0.4.1

Currently CI pulls these haskell packages from various sources
including Ubuntu apt-get package database, manually installing debs,
and running `cabal install foo` using two different Cabal versions.

This barely works, and those versions are not compatible.
The closest compatible combination requires bumping hlint to 1.9.27.

The dependencies have been placed into a `coala-bears.cabal` so they
can be easily fetched and installed using `cabal install`, which
will look for a combination of versions that meets all criteria.

On Travis, removing 'haskell-platform' from the apt-get package list
reduces the number of packages fetched, most of which were not
the correct version needed by the coala dependencies.
Removing this prevents conflicts, and speeds up the build.
Instead 'happy' is added as this is an executable needed to build
the dependencies.

Using cabal properly with a .cabal file also solves the
cabal caching problems.

Fixes #1380

.ci/deps.cabal.sh

@@ -0,0 +1,11 @@
+set -e
+
+# cabal-install 1.22 is the minimum tested version
+cabal --version
+
+cabal update
+
+cabal install --only-dependencies --avoid-reinstalls
+
+# Force ghc-mod to resolve its Cabal version
+~/.cabal/bin/ghc-mod modules

.ci/deps.sh

@@ -31,9 +31,6 @@ case $CIRCLE_BUILD_IMAGE in
 
     # The non-apt go provided by Circle CI is acceptable
     deps=${deps/golang-go/}
-    # Add packages which are available in xenial
-    # The xenial hlint is >= 1.9.1
-    deps="$deps hlint"
     # Add packages which are already in the precise image
     deps="$deps g++-4.9 libxml2-utils php-codesniffer"
     # gfortran on CircleCI precise is 4.6 and R irlba compiles ok,
@@ -82,27 +79,14 @@ fi
 # Change environment for flawfinder from python to python2
 sudo sed -i '1s/.*/#!\/usr\/bin\/env python2/' /usr/bin/flawfinder
 
-# Update hlint to latest version (not available in apt)
-if [[ -z "$(which hlint)" ]]; then
-  hlint_deb=$(ls -vr ~/.apt-cache/hlint_1.9.* 2>/dev/null | head -1)
-  if [[ -z "$hlint_deb" ]]; then
-    hlint_deb_filename=hlint_1.9.26-1_amd64.deb
-    # This is the same build as xenial hlint
-    hlint_deb_url="https://launchpad.net/ubuntu/+source/hlint/1.9.26-1/+build/8831318/+files/${hlint_deb_filename}"
-    hlint_deb=~/.apt-cache/$hlint_deb_filename
-    wget -O $hlint_deb $hlint_deb_url
-  fi
-  sudo dpkg -i $hlint_deb
-fi
-
-# cabal update to 1.22.9.0 and install ghc-mod 5.6.0
-if [[ -z "$(which ghc-mod)" ]]; then
-  cabal update && cabal install cabal-install-1.22.9.0
-  cabal install ghc-mod
-fi
-
 # NPM commands
-sudo rm -rf $(which alex)  # Delete ghc-alex as it clashes with npm deps
+ALEX=$(which alex || true)
+# Delete 'alex' if it is not in a node_modules directory,
+# which means it is ghc-alex.
+if [[ -n "$ALEX" && "${ALEX/node_modules/}" == "${ALEX}" ]]; then
+  echo "Removing $ALEX"
+  sudo rm -rf $ALEX
+fi
 npm install
 
 # R commands

.travis.yml

@@ -17,14 +17,14 @@ addons:
       - avsm  # OPAM stable
       - hvr-ghc  # Haskell
     packages:
-      - cabal-install
+      - cabal-install-1.24
       - chktex
       - clang-3.4
       - cppcheck
       - flawfinder
       - gfortran
       - ghc
-      - haskell-platform
+      - happy
       - indent
       - libblas-dev
       - liblapack-dev
@@ -43,6 +43,8 @@ cache:
   directories:
     # Installed language package caches
     - ~/.cabal
+    - ~/.ghc
+    - ~/.ghc-mod
     - ~/R/Library
     - ~/.julia
     - $TRAVIS_BUILD_DIR/node_modules
@@ -51,8 +53,6 @@ cache:
     # coala managed data
     - ~/nltk_data
     - ~/.local/share/coala-bears
-    # .deb cache
-    - ~/.apt-cache
     # Installed linters
     - ~/infer-linux64-v0.7.0
     - ~/pmd-bin-5.4.1
@@ -66,7 +66,7 @@ env:
     - USE_PPAS="marutter/rdev staticfloat/juliareleases ondrej/golang"
     - R_LIB_USER=~/R/Library
     - LINTR_COMMENT_BOT=false
-    - PATH="$PATH:$TRAVIS_BUILD_DIR/node_modules/.bin:$TRAVIS_BUILD_DIR/vendor/bin:$HOME/dart-sdk/bin:$HOME/.cabal/bin:$HOME/infer-linux64-v0.7.0/infer/bin:$HOME/pmd-bin-5.4.1/bin:$HOME/bakalint-0.4.0:$HOME/.local/tailor/tailor-latest/bin"
+    - PATH="/opt/cabal/1.24/bin:$PATH:$TRAVIS_BUILD_DIR/node_modules/.bin:$TRAVIS_BUILD_DIR/vendor/bin:$HOME/dart-sdk/bin:$HOME/.cabal/bin:$HOME/infer-linux64-v0.7.0/infer/bin:$HOME/pmd-bin-5.4.1/bin:$HOME/bakalint-0.4.0:$HOME/.local/tailor/tailor-latest/bin"
 
 before_install:
   - export TRAVIS_PYTHON_VERSION_MAJOR=${TRAVIS_PYTHON_VERSION%.[0-9]}
@@ -80,9 +80,8 @@ before_install:
   - nvm use 4
   # Remove Ruby directive from Gemfile as this image has 2.2.5
   - sed -i '/^ruby/d' Gemfile
-  - mkdir -p ~/.apt-cache
   - if [[ "$UNSUPPORTED" != true ]]; then bash .ci/deps.sh; fi
-  - if [[ "$UNSUPPORTED" != true ]]; then bash .ci/deps.shellcheck.sh; fi
+  - if [[ "$UNSUPPORTED" != true ]]; then bash .ci/deps.cabal.sh; fi
   # https://github.com/coala/coala/issues/3183
   - cp requirements.txt requirements.orig
   - cat test-requirements.txt docs-requirements.txt bear-requirements.txt >> requirements.txt

circle.yml

@@ -1,6 +1,5 @@
 dependencies:
   cache_directories:
-    - ~/.apt-cache
     - ~/.pyenv/versions/3.4.3
     - ~/.pyenv/versions/3.5.1
     - ~/coala-bears/node_modules
@@ -9,6 +8,8 @@ dependencies:
     - ~/.RLibrary
     - ~/dart-sdk/bin
     - ~/.cabal
+    - ~/.ghc
+    - ~/.ghc-mod
     - ~/infer-linux64-v0.7.0
     - ~/nltk_data
     - ~/pmd-bin-5.4.1
@@ -32,7 +33,7 @@ dependencies:
     - mkdir -p ~/.RLibrary
     - nvm alias default node
   override:
-    - bash .ci/deps.shellcheck.sh
+    - bash .ci/deps.cabal.sh
     - bash .ci/deps.sh:
         timeout: 900  # Allow 15 mins before timing out due to "no output"
 

coala-bears.cabal

@@ -0,0 +1,13 @@
+Name: coala-bears
+Version: 0.10
+cabal-version: >= 1.2
+build-type: Simple
+
+-- safe 0.3.9 is needed to coexist with Cabal 1.16
+-- safe 0.3.10 requires Cabal 1.18
+
+-- Note trusty apt package "haskell-platform" includes mtl-2.1.2
+-- which is incompatible with ShellCheck 0.4.1 which needs mtl-2.2.1
+
+library
+  build-depends: base, Cabal>=1.16, safe==0.3.9, ghc-mod==5.6.0.0, hlint==1.9.27, ShellCheck==0.4.1