Cannot add a custom cartridge

[edoput]

rhc version:

rhc --version
rhc 0.0.0

I guess this is the packaged version in debian

expected result:

add a custom cartridge from the cartridge manifests url

actual result:

adding a custom cartridge is not possible due to an error in a regular expression

steps to reproduce:

add a custom cartridge such as http://rqbuilder-edoput.rhcloud.com/ to a existing application.

The error is

edoput@bender:~/repo/rqbuilder (vendor_problem)$rhc cartridge add http://builder-edoput.rhcloud.com/manifest/f0a527d4ecfbaaa0ca007e4c167c82694709b465 -a python
The cartridge
'http://rqbuilder-edoput.rhcloud.com/manifest/f0a527d4ecfbaaa0ca007e4c167c82694709b465'
will be downloaded and installed
Adding
http://rqbuilder-edoput.rhcloud.com/manifest/f0a527d4ecfbaaa0ca007e4c167c82694709b465
to application 'python' ...
The provided downloadable cartridge
'http://rqbuilder-edoput.rhcloud.com/manifest/f0a527d4ecfbaaa0ca007e4c167c82694709b465'
cannot be loaded: Cartridge-Vendor 'EdoPut' does not match pattern
/\A[a-z0-9](?:[a-z0-9_]*[a-z0-9]|)\z/.

the field vendor-name cannot be unset but keeps popping this stange error and its regex pattern