haskellPackages.Agda: Fix build for ghc 8.10.2 → 8.10.3 upgrade

Commit 1998b95adc “haskellPackages:
update default compiler from ghc 8.10.2 to version 8.10.3” broke Agda
because Agda.cabal incorrectly declares a transformers dependency only
for ghc < 8.10.3:

    if impl(ghc >= 8.6.4) && impl(ghc < 8.10.3)
      build-depends: transformers == 0.5.6.2

    if impl(ghc >= 8.4) && impl(ghc < 8.6.4)
      build-depends: transformers == 0.5.5.0

    if impl(ghc < 8.4)
      build-depends: transformers == 0.5.2.0

leading to this error:

    src/full/Agda/Utils/Maybe.hs:13:1: error:
    Could not load module ‘Control.Monad.Trans.Maybe’
    It is a member of the hidden package ‘transformers-0.5.6.2’.
    Perhaps you need to add ‘transformers’ to the build-depends in your .cabal file.
    Use -v (or `:set -v` in ghci) to see a list of the files searched for.
       |
    13 | import Control.Monad.Trans.Maybe
       | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
This commit is contained in:
Anders Kaseorg 2020-12-26 18:57:13 -08:00 committed by Peter Simons
parent 5c23d98bae
commit 20a63c490f

View file

@ -98,4 +98,10 @@ self: super: {
# Break out of "Cabal < 3.2" constraint.
stylish-haskell = doJailbreak super.stylish-haskell;
# Agda 2.6.1.2 only declares a transformers dependency for ghc < 8.10.3.
Agda = appendPatch super.Agda (pkgs.fetchpatch {
url = "https://github.com/agda/agda/commit/76278c23d447b49f59fac581ca4ac605792aabbc.patch";
sha256 = "1g34g8a09j73h89pk4cdmri0nb0qg664hkff45amcr9kyz14a9f3";
});
}