The freaky implementation was done that way in order to avoid unnecessary
re-builds of all Haskell packages by changing the wrapper script used
internally in those builds.
See <https://github.com/NixOS/nixpkgs/pull/466> for further details.
The previous implementation used the following tying-the-knot trickery to
override 'doCheck' to false for the given build:
cabalNoTest = {
mkDerivation = x: rec {
final = self.cabal.mkDerivation (self: (x final) // { doCheck = false; });
}.final;
};
That seemed to work, but for some reason it caused trouble with some builds --
not all -- that use jailbreakCabal. The problem was the 'stdenv' attribute
couldn't be evaluated properly anymore:
$ nix-build ~/pkgs/top-level/release-haskell.nix -A optparseApplicative.ghc6104.x86_64-linux --show-trace
error: while evaluating the attribute `drvPath' at `/nix/store/qkj5cxknwspz8ak0ganm97zfr2bhksgn-nix-1.5.2pre3082_2398417/share/nix/corepkgs/derivation.nix:19:9':
while evaluating the builtin function `derivationStrict':
while instantiating the derivation named `haskell-optparse-applicative-ghc6.10.4-0.5.2.1' at `/home/simons/.nix-defexpr/pkgs/build-support/cabal/default.nix:40:13':
while evaluating the derivation attribute `configurePhase' at `/home/simons/.nix-defexpr/pkgs/build-support/cabal/default.nix:107:13':
while evaluating the function at `/home/simons/.nix-defexpr/pkgs/lib/strings.nix:55:26':
while evaluating the attribute `outPath' at `/nix/store/qkj5cxknwspz8ak0ganm97zfr2bhksgn-nix-1.5.2pre3082_2398417/share/nix/corepkgs/derivation.nix:18:9':
while evaluating the builtin function `getAttr':
while evaluating the builtin function `derivationStrict':
while instantiating the derivation named `jailbreak-cabal-1.1' at `/home/simons/.nix-defexpr/pkgs/build-support/cabal/default.nix:40:13':
while evaluating the derivation attribute `nativeBuildInputs' at `/home/simons/.nix-defexpr/pkgs/stdenv/generic/default.nix:76:17':
while evaluating the function at `/home/simons/.nix-defexpr/pkgs/lib/lists.nix:135:21':
while evaluating the attribute `buildInputs' at `/home/simons/.nix-defexpr/pkgs/build-support/cabal/default.nix:22:17':
while evaluating the builtin function `filter':
while evaluating the function at `/home/simons/.nix-defexpr/pkgs/build-support/cabal/default.nix:22:60':
while evaluating the function at `/home/simons/.nix-defexpr/pkgs/top-level/haskell-packages.nix:119:17':
while evaluating the function at `/home/simons/.nix-defexpr/pkgs/lib/customisation.nix:61:22':
while evaluating the function at `/home/simons/.nix-defexpr/pkgs/lib/customisation.nix:56:24':
while evaluating the builtin function `isAttrs':
while evaluating the function at `/home/simons/.nix-defexpr/pkgs/development/libraries/haskell/Cabal/1.14.0.nix:1:1':
while evaluating the function at `/home/simons/.nix-defexpr/pkgs/top-level/haskell-packages.nix:113:20':
while evaluating the attribute `final' at `/home/simons/.nix-defexpr/pkgs/top-level/haskell-packages.nix:114:7':
while evaluating the function at `/home/simons/.nix-defexpr/pkgs/build-support/cabal/default.nix:9:5':
while evaluating the function at `/home/simons/.nix-defexpr/pkgs/stdenv/generic/default.nix:51:24':
while evaluating the attribute `meta.license' at `/home/simons/.nix-defexpr/pkgs/development/libraries/haskell/Cabal/1.14.0.nix:17:5':
infinite recursion encountered
I tried to figure out why this happens, but eventually gave up. The new
implementation passes an argument called 'enableCheckPhase' to the Cabal
builder, which determines whether the user-specified doCheck value has any
effect or not. Now, a normal override can be used to disable unit testing.
