YUM not respecing my installation group

YUM not respecing my installation group

I've created a custom local repository. I'm attempting to install several
hundred custom RPMs by using a yum group, but a cursory attempt has
failed. yum is not recognizing my group. I've tried yum grouplist | grep
mygroup but it comes up empty.
I've made an rpm, and defined it's group as follows in groups.xml:
<!DOCTYPE comps PUBLIC "-//Red Hat, Inc.//DTD Comps info//EN" "comps.dtd">
<comps>
<group>
<id>mygroup</id>
<default>False</default>
<uservisible>True</uservisible>
<display_order>1024</display_order>
<name>mygroup</name>
<description></description>
<packagelist>
<packagereq type="mandatory">rpm1</packagereq>
...
<packagereq type="mandatory">rpmN</packagereq>
</packagelist>
</group>
</comps>
I create the repo in the correct directory using createrepo -g groups.xml.
Then I made the repo file in /etc/yum.repos.d which pointed to this location.
[JARSS]
name = This is the thing
baseurl = file:///this/is/the/path
I know this worked because commands like yum install rpmN work, but yum
groupinstall mygroup do not.
Any ideas?