gifn-apply: README: add a brief note about the Tox invocation
Not nearly enough, but still a start.
Change-Id: I14608c80f04bc828bddbf69637403cb977d03f6f
diff --git a/tools/git-if-needed/python/README.md b/tools/git-if-needed/python/README.md
index 5b68b7d..0588798 100644
--- a/tools/git-if-needed/python/README.md
+++ b/tools/git-if-needed/python/README.md
@@ -5,4 +5,16 @@
# gifn-apply - run git-if-needed on the specified repositories
-Mostly used for tests. This file needs more words.
+## Making sure OpenStack patches will apply cleanly
+
+Once the patch and series files in the top-level `patches/` tree of
+the `sp-osci` repository have been updated, run the `gifn-apply` tool
+against a set of OpenStack repositories:
+
+ tox -e functional-cinder
+
+If the `REPO_URL_OPENSTACK` environment variable is set, it will be used as
+the base directory to form the locations of the OpenStack Git repositories
+to check out for testing.
+
+This file still needs more words.