Both packages come with a library
test-support.el which provide the feature
test-support. The tools I use to maintain the Emacsmirror report this as a feature conflict.
The easiest fix would be to prefix the files/features to make them distinct.
These files are not intended to be loaded by end-users so they are not really "libraries" and they do not have to be loaded with
require. So a better fix might be to drop the
provide forms and load these files using
load instead, providing a relative path. That way you can keep the file-names without creating a conflict.