oeqa/selftest/imagefeatures: dump the JSON if it can't be parsed

(From OE-Core rev: 4f7c840349f576f3edb68b16f9bcc9d88bc73b36)

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/meta/lib/oeqa/selftest/cases/imagefeatures.py b/meta/lib/oeqa/selftest/cases/imagefeatures.py
index afc629f29c..8213d63e37 100644
--- a/meta/lib/oeqa/selftest/cases/imagefeatures.py
+++ b/meta/lib/oeqa/selftest/cases/imagefeatures.py
@@ -161,7 +161,8 @@ class ImageFeatures(OESelftestTestCase):
             sysroot = get_bb_var('STAGING_DIR_NATIVE', 'core-image-minimal')
             result = runCmd('qemu-img info --output json %s' % image_path,
                             native_sysroot=sysroot)
-            self.assertTrue(json.loads(result.output).get('format') == itype)
+            self.assertTrue(json.loads(result.output).get('format') == itype,
+                            msg="Could not parse '%s'" % result.output)
 
     def test_long_chain_conversion(self):
         """