treewide: Fix typos

This hook can be used to setup a check phase that

requires running a MPI application. It detects the

used present MPI implementaion type and exports

used present MPI implementation type and exports

the neceesary environment variables to use

`mpirun` and `mpiexec` in a Nix sandbox.

They can be installed either as a global tool for the entire system, or as a local tool specific to project.

The local installation is the easiest and works on NixOS in the same way as on other Linux distributions.

[See dotnet documention](https://learn.microsoft.com/en-us/dotnet/core/tools/global-tools#install-a-local-tool) to learn more.

[See dotnet documentation](https://learn.microsoft.com/en-us/dotnet/core/tools/global-tools#install-a-local-tool) to learn more.

[The global installation method](https://learn.microsoft.com/en-us/dotnet/core/tools/global-tools#install-a-global-tool)

should also work most of the time. You have to remember to update the `PATH`

interested in the alternative [haskell.nix] framework, which, be warned, is

completely incompatible with packages from `haskellPackages`.

<!-- TODO(@maralorn) Link to package set generation docs in the contributers guide below. -->

<!-- TODO(@maralorn) Link to package set generation docs in the contributors guide below. -->

## `haskellPackages.mkDerivation` {#haskell-mkderivation}

Since the interrelated parts, i.e. the package set and GHC, are connected

via the Nixpkgs fixpoint, we need to modify them both in a way that preserves

their connection (or else we'd have to wire it up again manually). This is

achieved by changing GHC and the package set in seperate overlays to prevent

achieved by changing GHC and the package set in separate overlays to prevent

the package set from pulling in GHC from `prev`.

The result is two overlays like the ones shown below. Adjustable parts are

   composer repository on the filesystem containing dependencies specified in

   `composer.json`. This process uses the function

   `php.mkComposerRepository` which in turn uses the

   `php.composerHooks.composerRepositoryHook` hook. Internaly this function uses

   `php.composerHooks.composerRepositoryHook` hook. Internally this function uses

   a custom

   [Composer plugin](https://github.com/nix-community/composer-local-repo-plugin) to

   generate the repository.

  Another benefit of the refactoring is that we can now issue reloads via either `pkill -HUP unbound` and `systemctl reload unbound` to reload the running configuration without taking the daemon offline. A prerequisite of this was that unbound configuration is available on a well known path on the file system. We are using the path `/etc/unbound/unbound.conf` as that is the default in the CLI tooling which in turn enables us to use `unbound-control` without passing a custom configuration location.

  The module has also been reworked to be [RFC 0042](https://github.com/NixOS/rfcs/blob/master/rfcs/0042-config-option.md) compliant. As such, `sevices.unbound.extraConfig` has been removed and replaced by [services.unbound.settings](options.html#opt-services.unbound.settings). `services.unbound.interfaces` has been renamed to `services.unbound.settings.server.interface`.

  The module has also been reworked to be [RFC 0042](https://github.com/NixOS/rfcs/blob/master/rfcs/0042-config-option.md) compliant. As such, `services.unbound.extraConfig` has been removed and replaced by [services.unbound.settings](options.html#opt-services.unbound.settings). `services.unbound.interfaces` has been renamed to `services.unbound.settings.server.interface`.

  `services.unbound.forwardAddresses` and `services.unbound.allowedAccess` have also been changed to use the new settings interface. You can follow the instructions when executing `nixos-rebuild` to upgrade your configuration to use the new interface.