I've been using Vim Fugitive plugin for some time now. Recently, I tried the Vim rhubarb plugin.
So for a github-repo it should work out of the box but `:GBrowse doesn't open the browser at all.
:Gbrowse! seems to work fine.
I believe it has to do with vim version.
I'm using apple compiled vim
VIM - Vi IMproved 8.1 (2018 May 18, compiled Nov 9 2019 02:36:49)
Included patches: 1-503, 505-680, 682-1312