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5th chunk of `pkgs/development/haskell-modules/HACKING.md`
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    [`nixpkgs:haskell-updates`](https://hydra.nixos.org/jobset/nixpkgs/haskell-updates)
    jobset) every 4 hours.  It is possible to force a new Hydra evaluation without
    waiting 4 hours by the following steps:

    1. Log into Hydra with your GitHub or Google account.
    1. Go to the [nixpkgs:haskell-updates](https://hydra.nixos.org/jobset/nixpkgs/haskell-updates) jobset.
    1. Click the `Actions` button.
    1. Select `Evaluate this jobset`.
    1. If you refresh the page, there should be a new `Evaluation running since:` line.
    1. Evaluations take about 10 minutes to finish.

-   It is sometimes helpful to update the version of
    [`cabal2nix` / `hackage2nix`](https://github.com/NixOS/cabal2nix) that our
    maintainer scripts use.  This can be done with the
    [`maintainers/scripts/haskell/update-cabal2nix-unstable.sh`](../../../maintainers/scripts/haskell/update-cabal2nix-unstable.sh)
    script.

    You might want to do this if a user contributes a fix to `cabal2nix` that
    will immediately fix a Haskell package in Nixpkgs.  First, merge in
    the PR to `cabal2nix`, then run `update-cabal2nix-upstable.sh`.  Finally, run
    [`regenerate-hackage-packages.sh`](../../../maintainers/scripts/haskell/regenerate-hackage-packages.sh)
    to regenerate the Hackage package set with the updated version of `hackage2nix`.

-   Make sure never to update the Hackage package hashes in
    [`pkgs/data/misc/hackage/`](../../../pkgs/data/misc/hackage/), or the
    pinned Stackage Nightly versions on the release branches (like
    `release-21.05`).

    This means that the
    [`update-hackage.sh`](../../../maintainers/scripts/haskell/update-hackage.sh)
    and
    [`update-stackage.sh`](../../../maintainers/scripts/haskell/update-stackage.sh)
    scripts should never be used on the release branches.

    However, changing other files in `./.` and regenerating the package set is encouraged.
    This can be done with
    [`regenerate-hackage-packages.sh`](../../../maintainers/scripts/haskell/regenerate-hackage-packages.sh)
    as described above.

-   The Haskell team members generally hang out in the Matrix room
    [#haskell:nixos.org](https://matrix.to/#/#haskell:nixos.org).

-   This is a checklist for things that need to happen when a new
    member is added to the Nixpkgs Haskell team.

    1.  Add the person to the
        [@NixOS/haskell](https://github.com/orgs/NixOS/teams/haskell)
        team.  You may need to ask someone in the NixOS organization
        to do this, like [@domenkozar](https://github.com/domenkozar).
        This gives the new member access to the GitHub repos like
        [cabal2nix](https://github.com/NixOS/cabal2nix).

    1.  Add the person as a maintainer for the following packages
        on Hackage:
        - https://hackage.haskell.org/package/cabal2nix
        - https://hackage.haskell.org/package/distribution-nixpkgs
        - https://hackage.haskell.org/package/hackage-db
        - https://hackage.haskell.org/package/jailbreak-cabal
        - https://hackage.haskell.org/package/language-nix

    1.  Add the person to the `haskell` team in
        [`maintainers/team-list.nix`](../../../maintainers/team-list.nix).
        This team is responsible for some important packages in
        [release-haskell.nix](../../top-level/release-haskell.nix).

    1.  Update the
        [Nextcloud Calendar](https://cloud.maralorn.de/apps/calendar/p/H6migHmKX7xHoTFa)
        and work the new member into the `haskell-updates` rotation.

    1.  Optionally, have the new member add themselves to the Haskell
        section in [`OWNERS`](../../../ci/OWNERS).  This
        will cause them to get pinged on most Haskell-related PRs.
Title: Further Tips: Hydra Evaluation, cabal2nix Updates, Release Branches, and New Team Members
Summary
This section provides additional tips for Haskell package maintenance in Nixpkgs. It details how to force a Hydra evaluation, update cabal2nix, avoid updating Hackage hashes or Stackage versions on release branches, and regenerate the package set. It also provides information about the Haskell team's Matrix room and a checklist for adding new members to the Nixpkgs Haskell team, including GitHub team membership, Hackage maintainership, inclusion in `maintainers/team-list.nix`, and updating the Nextcloud calendar.