core/pkgs/build-support/fetchmtn/default.nix

# You can specify some extra mirrors and a cache DB via options
{ lib, stdenvNoCC, monotone, defaultDBMirrors ? [ ]
, cacheDB ? "./mtn-checkout.db" }:
# dbs is a list of strings
# each is an url for sync

# selector is mtn selector, like h:org.example.branch
#
{ name ? "mtn-checkout", dbs ? [ ], sha256, selector ? "h:" + branch, branch }:

stdenvNoCC.mkDerivation {
  builder = ./builder.sh;
  nativeBuildInputs = [ monotone ];

  outputHashAlgo = "sha256";
  outputHashMode = "recursive";
  outputHash = sha256;

  dbs = defaultDBMirrors ++ dbs;
  inherit branch cacheDB name selector;

  impureEnvVars = lib.fetchers.proxyImpureEnvVars;

}