stack-snapshots

NOTE this repo is now deprecated/archived. Nix/cabal are used to build haskell projects.

A repository to house useful custom stack snapshots, c.f.,https://docs.haskellstack.org/en/stable/custom_snapshot/ and https://www.fpcomplete.com/blog/2017/07/stacks-new-extensible-snapshots.

The hope is that this will be useful as our internal dependencies grow.

Usage

In your stack.yaml set resolver to

resolver: https://raw.githubusercontent.com/EarnestResearch/stack-snapshots/master/snapshots/er-lts-13.9.0.yaml

Approach

Custom snapshots are derived from upstream and include additional packages we wish to include as well as updated versions of official packages (generally bugfixes that are not yet visible upstream).

Add a new custom snapshot

Review the the status of the latest available, see if any of the customized dependencies got any updates and bump those up or remove them if the fixes are already upstream. Add a new snapshot by suffixing our patch number at the end of lts-x.y official version.

Motivation

The point of custom snapshots is to turn, e.g., this

# old stack.yaml
resolver: lts-12.7
extra-deps:
- git: git@github.com:brendanhay/amazonka
  commit: 248f7b2a7248222cc21cef6194cd1872ba99ac5d
  subdirs:
    - amazonka
    - core
    - amazonka-s3
- named-2.0

into its own snapshot that can be referenced thusly (or even from a URL)

# new stack.yaml
resolver: my-custom-snapshot.yaml

where

# my-custom-snapshot.yaml
resolver: lts-12.7
name: my-custom-snapshot.yaml
packages:
- git: git@github.com:brendanhay/amazonka
  commit: 248f7b2a7248222cc21cef6194cd1872ba99ac5d
  subdirs:
    - amazonka
    - core
    - amazonka-s3
- named-2.0

In doing so we're saying that we'd like our snapshot to start off from the package set (and GHC version) defined in lts-12.7, and in addition, add the specified packages.