Add a short sleep to release-testing for umount race condition

debian/changelog

@@ -1,3 +1,10 @@
+xen-tools (4.6.3~dev-1) UNRELEASED; urgency=medium
+
+  * New upstream development release
+    + release-testing: Work around umount race condition between tests.
+
+ -- Axel Beckert <abe@debian.org>  Thu, 24 Dec 2015 11:54:24 +0100
+
 xen-tools (4.6.2-1) unstable; urgency=medium
 
   * New upstream bugfix release

examples/release-testing

@@ -3,4 +3,6 @@
 # Skip dapper and edgy due to bug #659360 in debootstrap
 for dist in $(awk '!/^#|^$/ {print $1}' /etc/xen-tools/distributions.conf | egrep -v '^(dapper|edgy)$'); do
     xen-create-image --dist $dist --force --verbose "$@" || break
+    # Work around umount being sometimes too slow
+    sleep 2
 done 2>&1 | tee xen-tools-release-testing.log