prepare_iso: set -e and trap with a cleanup function
prepare_iso: set -e and trap with a cleanup function

epu/boxcutter-osx,boxcutter/osx,defn/basebox-osx,epu/boxcutter-osx,samepage-labs/osx-templates,boxcutter/osx,boxcutter/macos,boxcutter/osx,boxcutter/macos,samepage-labs/osx-templates,defn/basebox-osx,boxcutter/macos,samepage-labs/osx-templates,boxcutter/osx,boxcutter/osx,epu/boxcutter-osx,epu/boxcutter-osx,epu/boxcutter-osx,boxcutter/macos,samepage-labs/osx-templates,samepage-labs/osx-templates,boxcutter/macos