```erlang %% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*- %% ex: ts=4 sw=4 ft=erlang et ExtraDeps = [{retest, ".*", {git, "git://github.com/dizzyd/retest.git"}}], case os:getenv("REBAR_EXTRA_DEPS") of false -> CONFIG; _ -> case lists:keysearch(deps, 1, CONFIG) of {value, {deps, Deps}} -> NDeps = Deps ++ ExtraDeps, lists:keyreplace(deps, 1, CONFIG, {deps, NDeps}); false -> CONFIG ++ [{deps, ExtraDeps}] end end. ```