morte-1.7.1 in nixpkgs-19.09 is marked as broken

[y-taka-23]

On the beginning of Project3, the command for building morte throws an error:

$ nix-build '<nixpkgs>' --attr haskellPackages.morte --show-trace
error: while evaluating the attribute 'handled' at /nix/store/ccyx7vqs8w74hq336b21mv79s0fbg728-nixpkgs-19.09pre175347.02bb5e35eae/nixpkgs/pkgs/stdenv/generic/check-meta.nix:252:7:
while evaluating 'handleEvalIssue' at /nix/store/ccyx7vqs8w74hq336b21mv79s0fbg728-nixpkgs-19.09pre175347.02bb5e35eae/nixpkgs/pkgs/stdenv/generic/check-meta.nix:146:28, called from /nix/store/ccyx7vqs8w74hq336b21mv79s0fbg728-nixpkgs-19.09pre175347.02bb5e35eae/nixpkgs/pkgs/stdenv/generic/check-meta.nix:253:14:
Package ‘morte-1.7.1’ in /nix/store/ccyx7vqs8w74hq336b21mv79s0fbg728-nixpkgs-19.09pre175347.02bb5e35eae/nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix:156186 is marked as broken, refusing to evaluate.

a) For `nixos-rebuild` you can set
  { nixpkgs.config.allowBroken = true; }
in configuration.nix to override this.

b) For `nix-env`, `nix-build`, `nix-shell` or any other Nix command you can add
  { allowBroken = true; }
to ~/.config/nixpkgs/config.nix.

[Gabriella439]

@y-taka-23: Yeah, at this point dhall is now the successor to morte, so I recommend using that if that is okay with you. See:

• http://dhall-lang.org/
• https://github.com/dhall-lang/dhall-lang/

[y-taka-23]

Ay, so is the PR welcomed?

[Gabriella439]

@y-taka-23: Yeah, I'd still welcome a pull request to fix it

[int-index]

This should unbreak morte in nixpkgs: Gabriella439/Haskell-Morte-Library#88

[Gabriella439]

@int-index: Thank you! I just uploaded this to Hackage as morte-1.7.2