diff --git a/Makefile-tests.am b/Makefile-tests.am
index bb9a7b36..6fffdfa4 100644
--- a/Makefile-tests.am
+++ b/Makefile-tests.am
@@ -1,5 +1,7 @@
 include $(top_srcdir)/buildutil/glib-tap.mk
 
+AM_TESTS_ENVIRONMENT = UNINSTALLEDTESTS=1 builddir=$(abs_builddir)
+
 CLEANFILES += \
 	tests/setup-session.sh \
 	tests/compose/yum/empty tests/compose/yum/repodata/repomd.xml \
@@ -57,6 +59,8 @@ test_programs = \
 	tests/jsonutil			\
 	$(NULL)
 
+test_scripts = tests/test-ucontainer.sh
+
 installed_test_PROGRAMS += dbus-run-session
 dbus_run_session_SOURCES = tests/dbus-run-session.c
 
diff --git a/src/libpriv/rpmostree-core.c b/src/libpriv/rpmostree-core.c
index 920f8f6c..80ec8569 100644
--- a/src/libpriv/rpmostree-core.c
+++ b/src/libpriv/rpmostree-core.c
@@ -267,11 +267,17 @@ add_canonicalized_string_array (GVariantBuilder *builder,
           g_variant_builder_add (builder, "{sv}", notfound_key, g_variant_new_boolean (TRUE));
           return TRUE;
         }
-      else
+      else if (temp_error)
         {
           g_propagate_error (error, g_steal_pointer (&temp_error));
           return FALSE;
         }
+      else
+        {
+          g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                       "Key %s is empty", key);
+          return FALSE;
+        }
     }
 
   for (iter = input; iter && *iter; iter++)
diff --git a/tests/libtest.sh b/tests/libtest.sh
index 7b1cb387..c5053b28 100644
--- a/tests/libtest.sh
+++ b/tests/libtest.sh
@@ -18,6 +18,18 @@
 # Boston, MA 02111-1307, USA.
 
 SRCDIR=$(dirname $0)
+_cleanup_tmpdir () {
+    if test -f ${test_tmpdir}.test; then
+	rm ${test_tmpdir} -rf
+    fi
+}
+if test -n "${UNINSTALLEDTESTS:-}"; then
+   test_tmpdir=$(mktemp -d test.XXXXXX)
+   touch ${test_tmpdir}/.test
+   trap _cleanup_tmpdir EXIT
+   cd ${test_tmpdir}
+   export PATH=${builddir}:${PATH}
+fi   
 test_tmpdir=$(pwd)
 
 export G_DEBUG=fatal-warnings
@@ -30,11 +42,11 @@ export TEST_GPG_KEYID="472CDAFA"
 export TEST_GPG_KEYHOME=${SRCDIR}/gpghome
 export OSTREE_GPG_HOME=${TEST_GPG_KEYHOME}/trusted
 
-if test -n "${OT_TESTS_DEBUG}"; then
+if test -n "${OT_TESTS_DEBUG:-}"; then
     set -x
 fi
 
-if test -n "$OT_TESTS_VALGRIND"; then
+if test -n "${OT_TESTS_VALGRIND:-}"; then
     CMD_PREFIX="env G_SLICE=always-malloc valgrind -q --leak-check=full --num-callers=30 --suppressions=${SRCDIR}/ostree-valgrind.supp"
 fi
 
diff --git a/tests/test-ucontainer.sh b/tests/test-ucontainer.sh
new file mode 100755
index 00000000..b8ce7abb
--- /dev/null
+++ b/tests/test-ucontainer.sh
@@ -0,0 +1,84 @@
+#!/bin/bash
+#
+# Copyright (C) 2016 Colin Walters <walters@verbum.org>
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the
+# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+
+set -euo pipefail
+
+. $(dirname $0)/libtest.sh
+
+echo "1..2"
+
+rpm-ostree container init
+if test -d ${SRCDIR}/compose; then
+    composedatadir=${SRCDIR}/compose
+else
+    composedatadir=${SRCDIR}
+fi
+cp ${composedatadir}/test-repo.repo rpmmd.repos.d
+
+cat >empty.conf <<EOF
+[tree]
+ref=empty
+packages=empty
+repos=test-repo
+EOF
+
+rpm-ostree container assemble empty.conf
+assert_has_dir roots/empty.0
+ostree --repo=repo rev-parse empty
+echo "ok assemble"
+
+cat >nobranch.conf <<EOF
+[tree]
+packages=empty
+repos=test-repo
+EOF
+if rpm-ostree container assemble nobranch.conf 2>err.txt; then
+    assert_not_reached "nobranch.conf"
+fi
+
+cat >nopackages.conf <<EOF
+[tree]
+ref=empty
+packages=
+repos=test-repo
+EOF
+if rpm-ostree container assemble nopackages.conf 2>err.txt; then
+    assert_not_reached "nopackages.conf"
+fi
+
+cat >norepos.conf <<EOF
+[tree]
+ref=empty
+packages=empty
+EOF
+if rpm-ostree container assemble norepos.conf 2>err.txt; then
+    assert_not_reached "norepos.conf"
+fi
+
+cat >notfoundpackage.conf <<EOF
+[tree]
+ref=notfound
+packages=notfound
+repos=test-repo
+EOF
+if rpm-ostree container assemble notfound.conf 2>err.txt; then
+    assert_not_reached "notfound.conf"
+fi
+
+echo "ok error conditions"