An update to my previous report. I think that the issue is due to the changeset 23238 and how the new procedures command_exec and parse_environment in portutil.tcl are managing the unarchive.env variable and the pipes. With the release 1.4.0 of MacPorts, the assembled command was 'cd "/opt/local/var/db/dports/build/ _opt_local_var_db_dports_sources_rsync.rsync.darwinports.org_dpupdate_dp orts_archivers_unrar /work/destroot" && /usr/bin/gzip -d -c /opt/local/var/db/dports/ packages/darwin/powerpc/ unrar-3.7.4_0.powerpc.tgz | /usr/bin/tar -xvpf -' With the latest sources, the content of unarchive.env (the gzip command) is missing from the pipe: 'cd "/opt/local/var/db/dports/build/ _opt_local_var_db_dports_sources_rsync.rsync.darwinports.org_dpupdate_dp orts_archivers_unrar/ work/destroot" && /usr/bin/tar -xvpf -'.