backports.configparser.InterpolationMissingOptionError:
Bad value substitution: option 'docs-classicui' in section 'sources' contains an interpolation key 'buildout:directory' which is not a valid option name.
Raw value: 'git ${remotes:plone}/documentation.git pushurl=${remotes:plone_push}/documentation.git egg=false branch=classic-ui path=${buildout:directory}/documentation/classic-ui'
This is a workaround for issue https://github.com/plone/mr.roboto/issues/82 Should prevent this error with coredev 6.0 sources.cfg: