Having a similar issue. Ran a build earlier and it was queued for about an hour. Cancelled it and running again, this build has been queued for about 10 minutes. Android ran fine, iOS failed before and is queued currently.
Build ID: [id]
Edit: scratch that, it just completed successfully.
So this has now been solved with help from Expo, I had a npm package with flags that inported not only the ones I used but all 2500 of them. That prevented me from building only on iOS but not Android. This lack of error message is now on the Expo’s radar and will hopefully be dealt with in the future!
Thanks for good feedback and fast response Expo team!