Steps to reproduce:
1) Install latest fpb (commit 38db815c266a55f16d0bd821e8e141cdf8333256)
2) run fpb --build plugin_name
Here is listing of rpm package generated:
/var/www/nailgun/plugins/cisco_aci-1.0/repositories
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/centos
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/centos/.gitkeep
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/centos/lldpd-0.7.6-2.1.x86_64.rpm
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/centos/openstack-dashboard-gbp-2014.2-1.el6.noarch.rpm
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/centos/openstack-heat-gbp-2014.2-1.el6.noarch.rpm
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/centos/openstack-neutron-gbp-2014.2-1.el6.noarch.rpm
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/centos/python-apicapi-1.0.2-0.noarch.rpm
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/centos/python-django-horizon-gbp-2014.2-1.el6.noarch.rpm
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/centos/python-gbpclient-0.9.0-1.el6.noarch.rpm
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/.gitkeep
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/Packages
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/Packages.gz
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/lldpd_0.7.7-1_amd64.deb
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/neutron-driver-apic-agent.deb
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/neutron-driver-apic-svc.deb
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/neutron-driver-apic.deb
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/python-apicapi_1.0.2-1_all.deb
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/python-group-based-policy-automation_2014.2-1_all.deb
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/python-group-based-policy-ui_2014.2-1_all.deb
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/python-group-based-policy_2014.2-1_all.deb
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/python-python-group-based-policy-client_0.9.0-1_all.deb
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/repodata
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/repodata/2daa2f7a904d6ae04d81abc07d2ecb3bc3d8244a1e78afced2c94994f1b5f3ee-filelists.sqlite.bz2
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/repodata/401dc19bda88c82c403423fb835844d64345f7e95f5b9835888189c03834cc93-filelists.xml.gz
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/repodata/6bf9672d0862e8ef8b8ff05a2fd0208a922b1f5978e6589d87944c88259cb670-other.xml.gz
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/repodata/ad36b2b9cd3689c29dcf84226b0b4db80633c57d91f50997558ce7121056e331-primary.sqlite.bz2
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/repodata/d5630fb9d7f956c42ff3962f2e6e64824e5df7edff9e08adf423d4c353505d69-other.sqlite.bz2
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/repodata/dabe2ce5481d23de1f4f52bdcfee0f9af98316c9e0de2ce8123adeefa0dd08b9-primary.xml.gz
/var/www/nailgun/plugins/cisco_aci-1.0/repositories/ubuntu/repodata/repomd.xml
As you can see - folder "repodata" located under ubuntu directory and of course the repo is broken.
Also on installed node - the file
/etc/yum.repos.d/plugin_name contains wrong url (/ubuntu) instead of centos - that also breaks yum.
Checked fpb from master, works just fine, could you please send me a plugin, or just show what is in your metadata.yaml file?