Only one concurrent build allowed after moving to Xcode 9.0


#1

Hello,
We have recently started moving from Xcode 8.3.3 to Xcode 9.0. We are using the free plan for open source iOS projects (https://circleci.com/gh/wireapp). We used to have several concurrent builds running at the same time, but after moving to the newest image it seems there is only 1 build running at a time.
Is it a new limitation for the open-source plan?


#2