{
  stdenv,
  lib,
  idris2,
  makeBinaryWrapper,
}:
# Usage: let
#          pkg = idris2Packages.buildIdris {
#            src = ...;
#            ipkgName = "my-pkg";
#            idrisLibraries = [ ];
#          };
#        in {
#          lib = pkg.library { withSource = true; };
#          bin = pkg.executable;
#        }
#
{
  src,
  ipkgName,
  version ? "unversioned",
  idrisLibraries, # Other libraries built with buildIdris
  ...
}@attrs:

let
  # loop over idrisLibraries and normalize them by turning any that are
  # direct outputs of the buildIdris function into the `.library {}`
  # property.
  idrisLibraryLibs = map (
    idrisLib:
    if lib.isDerivation idrisLib then
      idrisLib
    else if builtins.isFunction idrisLib then
      idrisLib { }
    else if (builtins.isAttrs idrisLib && idrisLib ? "library") then
      idrisLib.library { }
    else
      throw "Found an Idris2 library dependency that was not the result of the buildIdris function"
  ) idrisLibraries;

  propagate =
    libs: lib.unique (lib.concatMap (nextLib: [ nextLib ] ++ nextLib.propagatedIdrisLibraries) libs);
  ipkgFileName = ipkgName + ".ipkg";
  idrName = "idris2-${idris2.version}";
  libSuffix = "lib/${idrName}";
  propagatedIdrisLibraries = propagate idrisLibraryLibs;
  libDirs = (lib.makeSearchPath libSuffix propagatedIdrisLibraries) + ":${idris2}/${idrName}";
  supportDir = "${idris2}/${idrName}/lib";
  drvAttrs = builtins.removeAttrs attrs [
    "ipkgName"
    "idrisLibraries"
  ];

  derivation = stdenv.mkDerivation (
    finalAttrs:
    drvAttrs
    // {
      pname = ipkgName;
      inherit version;
      src = src;
      nativeBuildInputs = [
        idris2
        makeBinaryWrapper
      ] ++ attrs.nativeBuildInputs or [ ];
      buildInputs = propagatedIdrisLibraries ++ attrs.buildInputs or [ ];

      env.IDRIS2_PACKAGE_PATH = libDirs;

      buildPhase = ''
        runHook preBuild
        idris2 --build ${ipkgFileName}
        runHook postBuild
      '';

      passthru = {
        inherit propagatedIdrisLibraries;
      } // (attrs.passthru or { });

      shellHook = ''
        export IDRIS2_PACKAGE_PATH="${finalAttrs.env.IDRIS2_PACKAGE_PATH}"
      '';
    }
  );

in
{
  executable = derivation.overrideAttrs {
    installPhase = ''
      runHook preInstall
      mkdir -p $out/bin
      scheme_app="$(find ./build/exec -name '*_app')"
      if [ "$scheme_app" = ''' ]; then
        mv -- build/exec/* $out/bin/
        chmod +x $out/bin/*
        # ^ remove after Idris2 0.8.0 is released. will be superfluous:
        # https://github.com/idris-lang/Idris2/pull/3189
      else
        cd build/exec/*_app
        rm -f ./libidris2_support.so
        for file in *.so; do
          bin_name="''${file%.so}"
          mv -- "$file" "$out/bin/$bin_name"
          wrapProgram "$out/bin/$bin_name" \
            --prefix LD_LIBRARY_PATH : ${supportDir} \
            --prefix DYLD_LIBRARY_PATH : ${supportDir}
        done
      fi
      runHook postInstall
    '';
  };

  library =
    {
      withSource ? false,
    }:
    let
      installCmd = if withSource then "--install-with-src" else "--install";
    in
    derivation.overrideAttrs {
      installPhase = ''
        runHook preInstall
        mkdir -p $out/${libSuffix}
        export IDRIS2_PREFIX=$out/lib
        idris2 ${installCmd} ${ipkgFileName}
        runHook postInstall
      '';
    };
}