clean-old-stack-libs.sh: pushd seems a bashism
clean-old-stack-libs.sh: pushd seems a bashism

michalkonecny/stackage,jonschoning/stackage,simonmichael/stackage,asr/stackage,massysett/stackage,mrkkrp/stackage,fpco/stackage,iand675/stackage,clinty/stackage,soenkehahn/stackage,Daniel-Diaz/stackage