Failed to acquire virtual machine

http://ci-files01-hki.intra.qt.io:8080/coin/integration/qt/tqtc-qt5/tasks/1538809738

Coin failed to acquire a virtual machine, re-staging is unlikely to help, please contact the admins: 'Failed repeatedly to launch build/test agent'

This is causing lot's of failures and need to fixed asap. 

More info:

cat  /home/vmbuilder/ci-working-dir/logs/coin.log.2018-09-29 |grep "Failed to acquire machine and run agent within reasonable time"