Allow setting the HACKAGE2NIX environment variable to change the
hackage2nix the script uses to an absolute path to a local build. Useful
to test local changes in a realistic environment.
We split configuration-hackage2nix.yaml into multiple files. We bump
cabal2nix-unstable to get support for multiple config files in
hackage2nix.
* The file main.yaml is only supposed to be edited by humans.
* The file stackage.yaml is only supposed to be updated by the
update-stackage.sh
* The file broken.yaml can be edited by humans, but probably future
helpers will want to insert broken packages into this file based on
hydra reports.
* The file transitive-broken.yaml is newly introduced to be generated
by regenerate-transitive-broken-packages.sh
regenerate-transitive-broken-packages.sh makes a nix query (in
transitive-broken-packages.nix) which evaluates all haskellPackages
once with and once without "allowBroken" this way it get's a list of
packages which are broken by some transitive dependency, but does not
disable packages which have eval errors not caused by a broken package.
This is the preferred format for things fetched from git or similar that
are not proper releases: https://nixos.org/manual/nixpkgs/stable/#sec-package-naming
Also we should think about making name and attribute name more
consistent: cabal2nix-latest -> cabal2nix-unstable
Introduces a script that can be used to update the Nix expressions for
the Haskell package set. In service of that, also
- introduces cabal2nix-latest, which pins the hackage2nix version used
- changes all-cabal-hashes to use fetchFromGitHub
- adds update-hackage.sh & update-cabal2nix-latest.sh & update-stackage.sh maintainer scripts
