Composer / Adding custom "vcs" type of package source breaks deployment

Hi there,

I’m trying to use my fork of a WP plugin through adding a “vcs” type of repository

like this:

I’m struggling with a Composer failure at deploy time

all goes well if I run composer through the command line on the server but not when I’m deploying through capistrano

I was thinking it might have to do with Github credentials but I added a github token to my composer config without any luck

when changing capistrano/composer options to see what’s going on all I get is irrelevant messages that have nothing to to with the “vcs” repo

I know that the “vcs” is the cause of the failure because just by removing it all goes well again

was wondering if someone had a clue where I might have done something wrong or had faced a similar issue and could point me in the right direction

let me know if you need any more infos (like the gist of my composer.json for instance)