[DRE-maint] Bug#977825: gitlab: find a way to use yarn 2 with node_modules plugin

[Pirate Praveen]

Package: gitlab
Version: 13.4.7-2
Severity: important
Control: block -1 by 977781
Control: forwarded -1 https://github.com/yarnpkg/berry/issues/2258

yarnpkg is currently broken in unstable. A work around is to update to 
yarn 2, but its node-modules plugin refuse to work with node_modules as 
a symbolic link.

I have opened an upstream issue 
https://github.com/yarnpkg/berry/issues/2258