packcheck

Quick Start

Build on CI

To use packcheck for CI testing of your repo:

CircleCI

• Add your package repo to CircleCI as necessary (See https://circleci.com/docs/2.0/getting-started/)
• Copy .circleci/config.yml to your package repo

Appveyor

• Add your package repo to Appveyor as necessary (See https://www.appveyor.com/docs/server/)
• Copy appveyor.yml to your package repo

Github Actions

• Add your package repo to Github as necessary (See https://docs.github.com/en/actions/quickstart)
• Copy .github/workflows/packcheck.yml to your package repo

CI should work out of the box for most packages. Uncomment the relevant lines in the CI config files or change the values of the environment variables for fine grained control or custom configuration.

Build on Local Machine

You can use packcheck to build or CI test a package on your local machine as well. For local use, copy packcheck.sh to your local machine (Linux/OSX/Windows), put it in your PATH, and run it from your package directory. You can pass the same environment variables that are used in CI files to run the exact same tests locally. Usage is as simple as:

$ packcheck.sh cabal
$ packcheck.sh cabal GHCUP_VERSION=0.1.20.0 GHCVER=9.8.1
$ packcheck.sh stack GHCVER=9.4

packcheck can automatically pick the requested version of GHC from:

• multiple GHC path components in your PATH environment variable
• stack installed ghc binaries

Out of the box support

cabal	stack

Linux	OSX	Windows

Github	Appveyor	CircleCI	Local Machine

The script can be easily adapted to any CI with a single line build command.

Key Features

• Error messages: A lot of emphasis has been put on providing precise and detailed error messages when something fails so that the user can easily fix things.
• Informational: The output provides all the information that you may want to know, tool paths being used, their versions, how they are invoked, build options, time taken by each build step etc. You can even copy the commands from the output and paste them on your local host to reproduce the build or failure and debug quickly.
• Same tests everywhere: You can run exact same tests with same options or flags, in the same way, on all CI platforms.
• Choose options: Conveniently control all aspects of build through command line or environment variables, including tool options or whether to enable benchmarks, haddock, coverage, test etc.
• Picking GHC: Right GHC is picked up automatically from PATH or installed using ghcup by specifying GHCUP_VERSION and GHCVER env vars. Stack installed GHC binaries can be picked automatically when available.
• Test source distribution: packcheck creates the source distribution and builds the package from the generated tarball to make sure that you build what you release and don’t miss adding a file to the distribution. Also, checks if any file in the git repo is missing in the source distribution.

• Non-destructive: By default the script does not change any config or upgrade any tools on the host machine.
• Auto tool install: stack and ghc can be installed automatically

Introduction

The package packcheck includes a script called packcheck.sh, it is a high level universal super build script to uniformly, consistently build and comprehensively sanity test a Haskell package across build tools (stack/cabal) and across all platforms (Linux/MacOS/Windows). You do not need to be familiar with any of the build tools to use it.

To make sure that it works everywhere without installing anything it is deliberately written using the bash shell scripting language. Any of the parameters to control the builds can either be passed on the script command line or as environment variables for convenient use on CI systems.

packcheck is also a minimal yet complete “hello world” Haskell package with model config files that can be used unmodified in any Haskell package. The CI configs can be modified declaratively, using environment variables, to adapt to any kind of build scenario you can imagine.

This model package has everything that a Haskell package usually has; including tests, benchmarks and Linux/MacOS/Windows CI already working. It can be used as a starting point to develop a new package. Beginners can use it to learn about Haskell package metadata structure.

What all does it do?

An invocation of packcheck.sh performs a whole battery of tests, all aspects can be controlled via environment variables, command line. The flow goes roughly as follows:

• Pick or install the requested version of GHC/cabal/stack
• create source distribution package, unpack and test from it
• Check the differences in git repo and source distribution
• perform distribution checks
• build source
• build benchmarks
• build haddock docs
• run tests
• run hlint
• generate coverage report

Usage Examples

You can run these commands on your local machine as well as inside a CI script. You can try these commands in the packcheck package itself:

$ cd packcheck
$ ./packcheck.sh cabal GHCUP_VERSION=0.1.20.0 GHCVER=9.8.1

$ ./packcheck.sh stack RESOLVER=lts-21
$ ./packcheck.sh stack GHCVER=8.6.5
$ ./packcheck.sh stack RESOLVER=lts-21.24 STACK_YAML=stack-8.0.yaml STACK_BUILD_OPTIONS="--flag streamly:examples-sdl" CABALVER=3.10
# You can also do a cabal build using stack installed ghc:
$ stack exec ./packcheck.sh cabal RESOLVER=lts-21

Run hlint commands on the directories src and test:

$ ./packcheck.sh hlint HLINT_OPTIONS="lint" HLINT_TARGETS="src test"

Picking GHC versions

When GHCVER parameter is not specified, packcheck looks for a binary named ghc in your PATH environment variable. It uses first such binary found in PATH.

When GHCVER parameter is specified and is not set to head, it looks for ghc in the PATH and if GHCVER is a PREFIX of the actual version of ghc binary found then that ghc binary is used. Otherwise, packcheck tries to look for another ghc binary in the next PATH components until it finds a matching ghc version.

If GHCVER is set to head, packcheck looks for ghc-head as the compiler and does not check the numeric version of the compiler.

If GHCUP_VERSION is specified packcheck tries to use the existing ghcup to install the ghc, if ghcup is not found it installs the requested version and then installs the GHCVER using it.

If all of the above fails packcheck looks for ghc in the stack install locations.

packcheck-safe

packcheck-safe.sh is a more robust wrapper over packcheck.sh, it does not trust or use any environment variables, all environment needs to be specified explicitly on the command line. Therefore, it ensures better reproducibility.

It also catches any misspelled command line parameter names. For example, packcheck.sh won’t catch it if you typed GHCVWR=9.8 instead of GHCVER=9.8, it just assumes that GHCVER is not specified. packcheck-safe.sh would generate an error saying that GHCVWR is not recognized. Since it uses a clean environment you will have to specify PATH as well on the command line. For example,

$ ./packcheck-safe.sh cabal PATH=/bin:/usr/bin:/opt/ghc/bin

packcheck-remote

packcheck-remote.sh is a wrapper over packcheck.sh. It allows you to run packcheck on a remote repository by cloning it locally and optionally merging a branch into another branch (e.g. merging a PR branch into master).

$ ./packcheck-remote.sh --force \
    --remote=https://github.com/user/repo \
    --checkout=origin/master \
    --merge=origin/branch \
    --directory=./repo.packcheck \
    -- cabal GHCVER=9.8.1

Use ./packcheck-remote.sh --help for more information.

Full Reference

Please use cabal version 2.4 or later.

NOTE: Any of the parameters described below can either be passed on command line or as an environment variable. Passing options on command line is more convenient when running interactively, while environment variables are more convenient when running on a CI system.

$ packcheck.sh --help

--------------------------------------------------
Usage
--------------------------------------------------
packcheck.sh COMMAND [PARAMETER=VALUE ...]

For example:
packcheck.sh cabal GHCVER=9.8.1
packcheck.sh stack RESOLVER=lts GHC_OPTIONS="-O0 -Werror"
packcheck.sh hlint

Ask questions: https://app.gitter.im/#/room/#composewell_streamly:gitter.im
Report issues: https://github.com/composewell/packcheck/issues/new

Control parameters can either be passed on command line or exported
as environment variables. Parameters marked DESTRUCTIVE may modify
your global user config or state.

Boolean parameters can be specified as
y|Y|yes|Yes|YES|true|True|TRUE|on|On|ON for an affirmative value and as
n|N|no|No|NO|false|False|FALSE|off|Off|OFF or empty for a negative value.

--------------------------------------------------
Commands and flags
--------------------------------------------------
cabal                   : build using cabal
stack                   : build using stack
hlint                   : run hlint
clean                   : remove the .packcheck directory
cleanall                : remove .packcheck, .stack-work directories
help | --help | -h      : show this help message
--version               : show packcheck version

--------------------------------------------------
Selecting tool versions
--------------------------------------------------
GHCUP_VERSION           : [a.b.c.d] GHCUP version to install GHCVER if needed
GHCVER                  : [a.b.c | head] GHC version prefix (may not be enforced when using stack)
CABALVER                : [a.b.c.d] Cabal version (prefix) to use
STACKVER                : [a.b.c.d] Stack version (prefix) to use
STACK_UPGRADE           : [y] DESTRUCTIVE! Upgrades stack to latest version
RESOLVER                : Stack resolver to use for stack builds or cabal builds using stack
HLINT_VERSION           : Download a specific version binary of hlint instead of using one in PATH
DOCSPEC_URL             : cabal-docspec release URL to install at ~/.local/bin/cabal-docspec (see https://github.com/phadej/cabal-extras/releases/)

--------------------------------------------------
Where to find the required tools
--------------------------------------------------
PATH                    : [path] Set PATH explicitly for predictable builds

--------------------------------------------------
Specifying common tool options
--------------------------------------------------
GHCUP_GHC_OPTIONS       : Used as in "ghcup install ghc <GHCUP_GHC_OPTIONS> <version>"
GHC_OPTIONS             : Specify GHC options to use
SDIST_OPTIONS           : Arguments to stack/cabal sdist command

--------------------------------------------------
Specifying what to build
--------------------------------------------------
DISABLE_BENCH           : [y] Do not build benchmarks, default is to build but not run
DISABLE_TEST            : [y] Do not run tests, default is to run tests
DISABLE_DOCS            : [y] Do not build haddocks, default is to build docs
ENABLE_DOCSPEC          : [y] Run cabal-docspec after the cabal build
DISABLE_SDIST_BUILD     : [y] Do not build from source distribution
DISABLE_SDIST_PROJECT_CHECK: [y] Ignore project file and continue
DISABLE_SDIST_GIT_CHECK : [y] Do not compare source distribution with git repo
DISABLE_DIST_CHECKS     : [y] Do not perform source distribution checks

--------------------------------------------------
cabal options
--------------------------------------------------
CABAL_REINIT_CONFIG     : [y] DESTRUCTIVE! Remove old config to avoid incompatibility issues
CABAL_PROJECT           : Alternative cabal project file, path relative to project root
CABAL_BUILD_OPTIONS     : ADDITIONAL cabal v2-build options to append to defaults
CABAL_DISABLE_DEPS      : [y] Do not install dependencies, do not do cabal update
CABAL_BUILD_TARGETS     : cabal v2-build targets, default is 'all'
CABAL_CHECK_RELAX       : [y] Do not fail if cabal check fails on the package.
CABAL_HACKAGE_MIRROR    : DESTRUCTIVE! Specify an alternative mirror, modifies the cabal config file.

--------------------------------------------------
stack options
--------------------------------------------------
STACK_YAML              : Alternative stack config file path relative to project root
STACK_OPTIONS           : ADDITIONAL stack global options (e.g. -v) to append
STACK_BUILD_OPTIONS     : ADDITIONAL stack build command options to append

--------------------------------------------------
hlint options
--------------------------------------------------
HLINT_OPTIONS           : hlint arguments e.g.'--datadir=. lint'
HLINT_TARGETS           : target directories to run hlint on e.g. 'src test'

--------------------------------------------------
Coverage options
--------------------------------------------------
COVERAGE                : [y] Just generate coverage information

--------------------------------------------------
Diagnostics options
--------------------------------------------------
CHECK_ENV               : [y] Treat unknown env variables as error, used with env -i
BASE_TIME               : System time to be used as base for timeline reporting

Build fails if DISABLE_SDIST_BUILD is not set and the contents of the source distribution tar ball do not match the git repository contents. Either add any exceptions to .packcheck.ignore file or use DISABLE_SDIST_GIT_CHECK=y to disable this feature. Currently this check is done only if git and tar commands are available in the PATH.

Options marked DESTRUCTIVE! are fine in a CI environment. But on a local machine sometimes it may not be desirable as it will change the state of your global cabal config, so consider that before using these options.

By default cabal builds are done using sandboxes. It creates any temporary files or build artifacts inside .packcheck directory. See the clean and cleanall commands to release the temporary space.

stack is automatically installed and can be used to do cabal builds as well. If you specify BUILD=cabal and RESOLVER at the same time then the cabal build uses stack installed cabal and ghc, both are installed automatically when needed.

For pure cabal builds i.e. when BUILD=cabal and RESOLVER is not specified, cabal and ghc must be pre-installed on the system before building.

Diagnostics

Sometimes you may run into issues due to some environment variables unknowingly set or some command line parameters or env variables being misspelled and therefore silently ignored. To avoid any such issues the robust way to invoke packcheck is to use a clean environment using env -i and passing CHECK_ENV=y parameter. When this parameter is set unwanted/misspelled variables are detected and reported.

$ env -i CHECK_ENV=y ./packcheck.sh stack

For performance diagnostics packcheck prints the time elapsed from the beginning at each build step performed.