diff -ru baselayout-1.12.5.orig/etc/profile baselayout-1.12.5/etc/profile
--- baselayout-1.12.5.orig/etc/profile	2009-11-27 15:27:58 +0100
+++ baselayout-1.12.5/etc/profile	2009-11-27 15:34:14 +0100
@@ -137,6 +137,21 @@
 	done
 fi
 
+#
+# final finally set EPREFIX to our prefix if we don't have a local portage. this
+# was previously done by the startprefix script, but we want to be able to start
+# this environment by simply sourcing etc/profile with the correct shell.
+#
+if [[ -z "${EPREFIX}" ]]; then
+	if [[ ! -x "@GENTOO_PORTAGE_EPREFIX@"/usr/bin/emerge ]]; then
+		export EPREFIX="@GENTOO_PORTAGE_EPREFIX@"
+	fi
+elif [[ "${EPREFIX}" != "@GENTOO_PORTAGE_EPREFIX@" ]]; then
+	echo "WARNING: EPREFIX is set from environment to \"${EPREFIX}\"."
+	echo "         You are entering the prefix \"@GENTOO_PORTAGE_EPREFIX@\"."
+	echo "         Having EPREFIX set this way will probably render this environment unusable."
+fi
+
 unset _ro_root
 unset _ro_deps
 unset _ro_chained_path_vars