If you invoke with NOCACHE=1 we pass --no-cache in the argv to
docker.py but may still not force a rebuild if the dockerfile checksum
hasn't changed. By testing for its presence we can force builds
without having to manually remove the docker image.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 tests/docker/docker.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tests/docker/docker.py b/tests/docker/docker.py
index ee40ca04d9..aab1648cc5 100755
--- a/tests/docker/docker.py
+++ b/tests/docker/docker.py
@@ -261,7 +261,8 @@ class BuildCommand(SubCommand):
         tag = args.tag
 
         dkr = Docker()
-        if dkr.image_matches_dockerfile(tag, dockerfile):
+        if "--no-cache" not in argv and \
+           dkr.image_matches_dockerfile(tag, dockerfile):
             if not args.quiet:
                 print "Image is up to date."
         else:
-- 
2.13.0