In FusionForge 6.0.4, just after the MediaWiki plugin was installed, if one selects a project and adds the MediaWiki tool, any attempt to go to the MediaWiki tab results in the following message:
MediaWiki requires the PSR-3 logging library to be present. This library is not embedded directly in MediaWiki's git repository and must be installed separately by the end user. Please see mediawiki.org for help on installing the required components.
Web client : Firefox 45.4.0
It seems to be related with following entry:
However I suspect it is not an upstream issue but it is rather due to the specific installation of MediaWiki in FusionForge. I tried the following workaround:
ln -s /usr/share/mediawiki/vendor /usr/share/fusionforge/plugins/mediawiki
But no success.
This workaround was inspired by the quick fix given here: