Only one concurrent build allowed and general reliability issues

Feedback & Bug Reports
1

We are using the free plan for open source iOS projects (https://circleci.com/gh/wireapp). Up until early last week it was possible to have several concurrent builds, but lately we get only 1 at a time. The others are marked as “Not Running”, not “Scheduled” as before. Not sure if that is expected or not.

We also noticed that sometimes our builds time out when doing 'carthage bootstrap` (e.g. https://circleci.com/gh/wireapp/wire-ios-mocktransport/203) which never used to happen before…

Another issue is that testing fails after running a few tests - https://circleci.com/gh/wireapp/wire-ios-sync-engine/667. The test suite is all-green if run locally and it used to be quite stable on CircleCI as well (https://circleci.com/build-insights/gh/wireapp/wire-ios-sync-engine/develop).

2

It seems we got our concurrent builds back by specifying the latest point release of Xcode:

The old config that used to work fine until last week:

machine:
   xcode:
      version: "8.3"

But now everything is back to normal after specifying latest Xcode:

machine:
   xcode:
      version: "8.3.2"