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{ lib, pkgs, ... }:

let


  /* Realize drvDeps, then return drvOut if that succeds.
   * This can be used to make drvOut depend on the
   * build success of all drvDeps without making each drvDep
   * a dependency of drvOut.
   * => drvOut is not rebuilt if drvDep changes
   */
  drvSeqL =
    (drvDeps: drvOut:
      let
        drvOutOutputs = drvOut.outputs or [ "out" ];
      in
      pkgs.runCommandLocal drvOut.name
        {
          # we inherit all attributes in order to replicate
          # the original derivation as much as possible
          outputs = drvOutOutputs;
          passthru = drvOut.drvAttrs;
          # depend on drvDeps (by putting it in builder context)
          inherit drvDeps;
        }
        # the outputs of the original derivation are replicated
        # by creating a symlink to the old output path
        (lib.concatMapStrings
          (output: ''
            target=${lib.escapeShellArg drvOut.${output}}
            # if the target is already a symlink, follow it until it’s not;
            # this is done to prevent too many dereferences
            target=$(readlink -e "$target")
            # link to the output
            ln -s "$target" "${"$"}${output}"
          '')
          drvOutOutputs));

in
drvSeqL