• I am on the latest Poetry version.
• [ x I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: Ubuntu 18.04
• Poetry version: 1.0.0b1

Issue

#1285 introduced a regression.

When exporting groups specified by the --extras flag, sub-dependencies of these extra optional packages are not exported.