The purpose of this document is to describe how to set up the .travis.yml script in order to build and test your cabalized Haskell package with multiple GHC configurations.
At time of writing Travis-CI has support for building Haskell packages but only for a single GHC configuration (i.e. Haskell Platform 2012.2.0.0 with GHC 7.4.1). By following this guide, you can set up Travis-CI jobs which have access to the following GHC versions (all compiled for Ubuntu Linux 12.04 LTS 64-bit):
- GHC 6.12.3,
- GHC 7.0.1, GHC 7.0.2, GHC 7.0.3, GHC 7.0.4,
- GHC 7.2.1, GHC 7.2.2,
- GHC 7.4.1, GHC 7.4.2,
- GHC 7.6.1, GHC 7.6.2, GHC 7.6.3,
- GHC 7.8.1, GHC 7.8.2, GHC 7.8.3, GHC 7.8.4
- GHC 7.10.1, GHC 7.10.2, GHC 7.10.3
- GHC 8.0.1, GHC 8.0.2
- GHC 8.2.1, GHC 8.2.2
- GHC 8.4.1, GHC 8.4.2, GHC 8.4.3, GHC 8.4.4
- GHC 8.6.1, GHC 8.6.2, GHC 8.6.3, GHC 8.6.4, GHC 8.6.5
- GHC 8.8.1, GHC 8.8.2, GHC 8.8.3, GHC-8.8.4
- GHC 8.10.1, GHC-8.10.2, GHC-8.10.3
- GHC HEAD.
Each GHC version is provided in a separate ghc-<version> .deb package installing into /opt/ghc/<version> (thus allowing to be installed at the same time if needed) published in a PPA. The easiest way to "activate" a particular GHC version is to prepend its bin-folder to the $PATH environment variable (see example in next section).
Note: For actually enabling continuous integration for a GitHub hosted project, see section Getting Started in Travis-CI's online documentation.
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Step 1: Clone and install this project in/from any directory
$ git clone https://github.com/haskell-CI/haskell-ci.git $ cd haskell-ci $ cabal new-install haskell-ci:exe:haskell-cior
cabal new-install haskell-ci
Note: currently (2019-02-12) released version of
haskell-ciinstalls an executable namedmake-travis-yml -
Step 2: Change directories to your project:
$ cd path/to/your-project -
Step 3: Edit your project's
*.cabalfile to add aTested-Withline, such as this one:$ cat your-project.cabal ... Tested-With: GHC ==8.6.3 || ==8.4.4 || ==8.2.2 ...
Add as many or as few GHC versions to test as you want.
-
Step 4: Generate a Travis file for your project:
$ # You run the following command from your project's directory, even $ # though it references the script from the `haskell-ci` project $ haskell-ci your-project.cabal --output .travis.yml
Note: If you have multiple local Cabal projects that you wish to build together using a
cabal.projectfile, pass that file to haskell-ci instead:$ haskell-ci cabal.project --output .travis.yml
The
haskell-citool looks at theTested-Withline in your*.cabalfiles and generates a Travis build that tests each compiler version you listed in parallel. -
Step 5: Create a branch with your new Travis file and push your branch:
$ git checkout master # Check out `master` $ git pull --ff-only # Get the latest version of `master` $ git checkout -b new_travis # Create a `new_travis` branch $ git add .travis.yml $ git commit -m "New Travis script" $ git push -u origin new_travis # Push your branch upstream
If you have Travis enabled for your repository this will test your branch using your newly created Travis file. This lets you test the Travis script before merging the new script into
master. -
Step 6: Fix the build
If you're lucky, your repository will build for every compiler version you listed. If that's the case, then just merge your changes into
master:$ git checkout master $ git merge new_travis # Update `master` with your new Travis script $ git pushYou can also merge your branch into
masterfrom Github's pull request view.If you're not lucky, then your new Travis branch will fail for one or more versions of GHC, which is okay! Look at the build and fix any build failures you find and commit the fixes to your branch:
$ # Fix any build failures you find and commit your changes $ ... $ git push # Push your branch updates upstream
Sometimes you may need to regenerate Travis script. for example, to remove the
cabal checkstep (pass--no-cabal-checkflag tohaskell-ci) if you know for sure that you need build your project with the-O2` flag.Each time you push an update to your branch Travis will run again to see if any build failures still remain. Repeat this process until your project builds against each GHC version you listed. Once your project builds against each target version of GHC you can merge your Travis script into
master
For convenience, a few add-on packages are available to provide more recent versions of cabal, alex and happy than are available in Ubuntu 12.04.
They install into a respective /opt/<name>/<version>/bin folder (see table below) which can be put into the search $PATH.
There's also a /opt/ghc/bin (& /opt/cabal/bin) folder which contains version-suffixed symlinks to installed GHC versions for convenient use with cabal (e.g. "cabal new-build -w ghc-7.8.4"), as well as symlinks managed by update-alternatives(1) which can be configured via
sudo update-alternatives --config opt-ghc
sudo update-alternatives --config opt-cabal
Note that /opt/ghc/bin also contains a default symlink for cabal, so it's enough to include /opt/ghc/bin in your PATH to get access to both cabal and ghc.
.deb Package Name |
Executable |
|---|---|
cabal-install-1.16 |
/opt/cabal/1.16/bin/cabal |
cabal-install-1.18 |
/opt/cabal/1.18/bin/cabal |
cabal-install-1.20 |
/opt/cabal/1.20/bin/cabal |
cabal-install-1.22 |
/opt/cabal/1.22/bin/cabal |
cabal-install-1.24 |
/opt/cabal/1.24/bin/cabal |
cabal-install-2.0 |
/opt/cabal/2.0/bin/cabal |
cabal-install-2.2 |
/opt/cabal/2.2/bin/cabal |
cabal-install-2.4 |
/opt/cabal/2.4/bin/cabal |
cabal-install-head |
/opt/cabal/head/bin/cabal |
alex-3.1.3 |
/opt/alex/3.1.3/bin/alex |
alex-3.1.4 |
/opt/alex/3.1.4/bin/alex |
alex-3.1.7 |
/opt/alex/3.1.7/bin/alex |
happy-1.19.3 |
/opt/happy/1.19.3/bin/happy |
happy-1.19.4 |
/opt/happy/1.19.4/bin/happy |
happy-1.19.5 |
/opt/happy/1.19.5/bin/happy |
See examples below for how to use those.
Since 2015, Travis-CI is migrating build-jobs towards a contained-based infrastructure which requires a different way to setup the build-matrix in the first half of the .travis.yml.
The following .travis.yml snippet shows the different matrix and
before_install sections (relative to the non-container
.travis.yml):
language: c
# explicitly request container-based infrastructure
sudo: false
matrix:
include:
- env: CABALVER=1.16 GHCVER=7.6.3
addons: {apt: {packages: [cabal-install-1.16,ghc-7.6.3], sources: [hvr-ghc]}}
- env: CABALVER=1.18 GHCVER=7.8.4
addons: {apt: {packages: [cabal-install-1.18,ghc-7.8.4], sources: [hvr-ghc]}}
- env: CABALVER=1.22 GHCVER=7.10.1
addons: {apt: {packages: [cabal-install-1.22,ghc-7.10.1],sources: [hvr-ghc]}}
- env: CABALVER=head GHCVER=head
addons: {apt: {packages: [cabal-install-head,ghc-head], sources: [hvr-ghc]}}
allow_failures:
- env: CABALVER=head GHCVER=head
before_install:
- export PATH=/opt/ghc/$GHCVER/bin:/opt/cabal/$CABALVER/bin:$PATHThe top-level tested-with: field has a similiar syntax to the build-depends: field but with compilers instead of packages. The script contains a list of known GHC versions and emits entries for all matching versions. Here are a few examples:
tested-with: GHC >= 7.4 && < 7.8
-- selects GHC 7.4.1, 7.4.2, 7.6.1, 7.6.2, and 7.6.3
tested-with: GHC == 7.4.2, GHC == 7.6.3, GHC == 7.8.4, GHC == 7.11.*
-- selects GHC 7.4.2, 7.6.3, 7.8.4, and GHC HEAD
If you need additional Ubuntu packages installed (e.g. alex-3.1.5 or libxml-dev), you can pass the Ubuntu package names as additional commandline arguments after the .cabal filename argument.
-
The container environment reports 16 cores, causing
cabal's default configuration (jobs: $ncpus) to run into the GHC #9221 bug which can result in longer build-times. This can be workarounded by commenting out thejobs: $ncpusright aftercabal updatecreates that file:install: # ... - travis_retry cabal update - sed -i 's/^jobs:/-- jobs:/' ${HOME}/.cabal/config # ...
Below is a commented .travis.yml example that can be used as a template:
# NB: don't set `language: haskell` here
# explicitly request legacy non-sudo based build environment
sudo: required
# The following enables several GHC versions to be tested; often it's enough to test only against the last release in a major GHC version. Feel free to omit lines listings versions you don't need/want testing for.
env:
- CABALVER=1.16 GHCVER=6.12.3
- CABALVER=1.16 GHCVER=7.0.1
- CABALVER=1.16 GHCVER=7.0.2
- CABALVER=1.16 GHCVER=7.0.3
- CABALVER=1.16 GHCVER=7.0.4
- CABALVER=1.16 GHCVER=7.2.1
- CABALVER=1.16 GHCVER=7.2.2
- CABALVER=1.16 GHCVER=7.4.1
- CABALVER=1.16 GHCVER=7.4.2
- CABALVER=1.16 GHCVER=7.6.1
- CABALVER=1.16 GHCVER=7.6.2
- CABALVER=1.18 GHCVER=7.6.3
- CABALVER=1.18 GHCVER=7.8.1 # see note about Alex/Happy for GHC >= 7.8
- CABALVER=1.18 GHCVER=7.8.2
- CABALVER=1.18 GHCVER=7.8.3
- CABALVER=1.18 GHCVER=7.8.4
- CABALVER=1.22 GHCVER=7.10.1
- CABALVER=1.22 GHCVER=7.10.2
- CABALVER=head GHCVER=head # see section about GHC HEAD snapshots
# Note: the distinction between `before_install` and `install` is not important.
before_install:
- travis_retry sudo add-apt-repository -y ppa:hvr/ghc
- travis_retry sudo apt-get update
- travis_retry sudo apt-get install cabal-install-$CABALVER ghc-$GHCVER # see note about happy/alex
- export PATH=/opt/ghc/$GHCVER/bin:/opt/cabal/$CABALVER/bin:$PATH
install:
- cabal --version
- echo "$(ghc --version) [$(ghc --print-project-git-commit-id 2> /dev/null || echo '?')]"
- travis_retry cabal update
- cabal install --only-dependencies --enable-tests --enable-benchmarks
# Here starts the actual work to be performed for the package under test; any command which exits with a non-zero exit code causes the build to fail.
script:
- if [ -f configure.ac ]; then autoreconf -i; fi
- cabal configure --enable-tests --enable-benchmarks -v2 # -v2 provides useful information for debugging
- cabal build # this builds all libraries and executables (including tests/benchmarks)
- cabal test
- cabal check
- cabal sdist # tests that a source-distribution can be generated
# Check that the resulting source distribution can be built & installed.
# If there are no other `.tar.gz` files in `dist`, this can be even simpler:
# `cabal install --force-reinstalls dist/*-*.tar.gz`
- SRC_TGZ=$(cabal info . | awk '{print $2;exit}').tar.gz &&
(cd dist && cabal install --force-reinstalls "$SRC_TGZ")
For more information about the .travis.yml script please consult the
official documentation.
Basic idea: Generate a cabal.config file during the build job (before installing the build-dependencies) constraining to HP package versions, e.g. for HP 2013.2.0.0 the cabal.config would need to contain the following constraints definition:
constraints: async==2.0.1.4,attoparsec==0.10.4.0,case-insensitive==1.0.0.1,cgi==3001.1.7.5,fgl==5.4.2.4,GLUT==2.4.0.0,GLURaw==1.3.0.0,haskell-src==1.0.1.5,hashable==1.1.2.5,html==1.0.1.2,HTTP==4000.2.8,HUnit==1.2.5.2,mtl==2.1.2,network==2.4.1.2,OpenGL==2.8.0.0,OpenGLRaw==1.3.0.0,parallel==3.2.0.3,parsec==3.1.3,QuickCheck==2.6,random==1.0.1.1,regex-base==0.93.2,regex-compat==0.95.1,regex-posix==0.95.2,split==0.2.2,stm==2.4.2,syb==0.4.0,text==0.11.3.1,transformers==0.3.0.0,unordered-containers==0.2.3.0,vector==0.10.0.1,xhtml==3000.2.1,zlib==0.5.4.1
Use this .travis.yml script as a template if you want
to test against Haskell Platform configurations.
If your package (or one of its dependencies) contain Alex/Happy generated parsers, GHC 7.8.1 and later require a more recent alex/happy executable installed (see Happy, Alex, and GHC 7.8 for the gory details). The following snipped (stolen from lens's .travis.yaml) illustrates how to this can be accomplished:
- |
if [ $GHCVER = "head" ] || [ ${GHCVER%.*} = "7.8" ] || [ ${GHCVER%.*} = "7.10" ]; then
travis_retry sudo apt-get install happy-1.19.4 alex-3.1.3
export PATH=/opt/alex/3.1.3/bin:/opt/happy/1.19.4/bin:$PATH
else
travis_retry sudo apt-get install happy alex
fi-
Snapshots of current GHC development snapshots from the
masterbranch (aka GHC HEAD) are uploaded at irregular intervals to the PPA -
You can select GHC HEAD at your own risk by setting
GHCVER=head -
As GHC HEAD is experimental and likely to cause build failures, you might want to tolerate failures by adding the following snippet to your
.travis.yml:matrix: allow_failures: - env: CABALVER=head GHCVER=head
-
NB: the line in
matrix.allow_failures.envmust match exactly (including any whitespace) the line specified inenv
- Check for
build-dependsexcluding latest package versions withpackdeps - Check for unused
build-dependswithpackunused - Check for 100% Haddock coverage
- Check for trailing whitespaces and/or tabs in source files
- If you want to know which core library version each GHC used (e.g. for deciding on what upper/lower bounds to declare for
build-depends), see GHC Boot Library Version History - Supporting GHC versions prior to 7.0.1 requires more effort:
- GHC 7.0.1 was the first version to support
default-language: Haskell2010 - Declaring
cabal-version >= 1.10makes it more difficult to compile with GHC 6.12.3's defaultcabal-install cabal-installfalls back to top-down solver for GHC < 7 which may require additional tweaks to the build script to compensate for (e.g. installingQuickCheckviacabal install --only-depis known to fail)
- GHC 7.0.1 was the first version to support






