Describe the bug
On the nixpkgs-unstable branch, when there are no haskell dependencies other than base (and other common ones like text) in build-depends in the cabal file, starting a shell with hoogle enabled gives the error:
error: value is null while a set was expected, at /nix/store/<hash>-source/pkgs/development/haskell-modules/hoogle.nix:69:43
To Reproduce
Steps to reproduce the behavior:
- Create the following
default.nix:
{ pkgs ? import <nixpkgs> {} }:
let
nixpkgs-src = pkgs.fetchFromGitHub {
owner = "NixOS";
repo = "nixpkgs";
rev = "nixpkgs-unstable";
sha256 = "06755h2cxrsgrsiclxbk3h5d7yqajvjjq3y4pl1dqbxfbjhq0h67";
};
nixpkgs = import nixpkgs-src {};
haskellPackages = nixpkgs.haskellPackages.override {
overrides = self: super:
{ testpkg = self.callCabal2nix "testpkg" ./. {}; };
};
shell = haskellPackages.shellFor {
packages = ps: [ ps.testpkg ];
buildInputs = [ haskellPackages.cabal-install ];
withHoogle = true;
};
in
if nixpkgs.lib.inNixShell then shell else haskellPackages.testpkg
- The following
testpkg.cabal:
cabal-version: 2.2
name: testpkg
version: 0.1.0.0
description: testpkg
build-type: Simple
library
exposed-modules:
other-modules:
Paths_testpkg
hs-source-dirs:
src
build-depends:
base >=4.7 && <5
-- uncomment the following to make it work
-- , lens
default-language: Haskell2010
- run
nix-shell
Expected behavior
The nix shell is initialized, and running hoogle server --local runs a hoogle server. Adding another dependency in build-depends, e.g. lens, results in the expected behaviour.
Additional context
The issue seems similar to this closed issue
Metadata
these paths will be fetched (0.00 MiB download, 0.00 MiB unpacked):
/nix/store/4cr2bqya0an66mpqpj195z49453qm8f6-nix-info
copying path '/nix/store/4cr2bqya0an66mpqpj195z49453qm8f6-nix-info' from 'https://cache.nixos.org'...
- system: `"x86_64-linux"`
- host os: `Linux 4.15.0-88-generic, Ubuntu, 16.04.6 LTS (Xenial Xerus)`
- multi-user?: `no`
- sandbox: `yes`
- version: `nix-env (Nix) 2.2.1`
- channels(alex): `"nixpkgs-20.03pre211462.0c960262d15"`
- nixpkgs: `/<redacted>/.nix-defexpr/channels/nixpkgs`
Maintainer information:
# a list of nixpkgs attributes affected by the problem
attribute:
- haskellPackages.shellFor
Describe the bug
On the
nixpkgs-unstablebranch, when there are no haskell dependencies other than base (and other common ones liketext) inbuild-dependsin the cabal file, starting a shell with hoogle enabled gives the error:To Reproduce
Steps to reproduce the behavior:
default.nix:testpkg.cabal:nix-shellExpected behavior
The nix shell is initialized, and running
hoogle server --localruns a hoogle server. Adding another dependency inbuild-depends, e.g.lens, results in the expected behaviour.Additional context
The issue seems similar to this closed issue
Metadata
Maintainer information: