clc-stackage

How to?

This is a meta-package to facilitate impact assessment for CLC proposals. The package clc-stackage.cabal lists almost entire Stackage as build-depends, so that cabal build transitively compiles them all.

An impact assessment is due when

1. Proposal makes a breaking change according to PVP.
2. Proposal exports a new entity from Prelude or other modules, described in Haskell Report.
3. On discretion of CLC members.

The procedure is as follows:

1. Rebase changes, mandated by your proposal, atop of ghc-9.8 branch.
2. Compile a patched GHC, say, ~/ghc/_build/stage1/bin/ghc.
3. git clone https://github.com/Bodigrim/clc-stackage, then cd clc-stackage.
4. Run cabal build -w ~/ghc/_build/stage1/bin/ghc --keep-going and wait for a long time.

• On a recent Macbook Air it takes around 12 hours, YMMV.
• You can interrupt cabal at any time and rerun again later.
• Consider setting --jobs to retain free CPU cores for other tasks.
• Full build requires roughly 7 Gb of free disk space.

5. If any packages fail to compile:

• copy them locally using cabal unpack,
• patch to confirm with your proposal,
• link them from packages section of cabal.project,
• return to Step 4.

6. When everything finally builds, get back to CLC with a list of packages affected and patches required.

Getting dependencies via nix

For Linux based systems, there's a provided flake.nix and shell.nix to get a nix shell with an approximation of the required dependencies (cabal itself, C libs) to build clc-stackage.

Note that it is not actively maintained, so it may require some tweaking to get working, and conversely, it may have some redundant dependencies.

Misc

• Your custom GHC will need to be on the PATH to build the stack library i.e.

  export PATH=/path/to/custom/ghc/stage1/bin/:$PATH
  

  Nix users can uncomment (and modify) this line in the flake.nix.