The command ./clone.py master -a -m "" --mp-only can fail or lead to unexpected behaviors because of a local configuration.
The --marketplace-conf allows to customize the "base" configuration, else the default one is used.
But in all cases, the local release.ini file will be read if exists and eventually overwrites the defaults.
Be more verbose, add the following output:
$ ./clone.py master -a -m "" --mp-only Read configuration from: 'https://raw.github.com/nuxeo/integration-scripts/master/marketplace.ini' Read configuration from: '/.../nuxeo/marketplace/release.ini' Configuration saved: '/.../nuxeo/marketplace/release.ini'