Workaround race condition with apt

[seibert]

Something is temporarily holding the dpkg lock on the Azure VMs when they first start up. This prevents the linux 32 config from apt-get installing something, but only some of the time. Adding a delay to hopefully avoid the conflict.

[seibert]

Pinging @chrisrpatterson: I'm not sure what is holding the Debian package lock when the Ubuntu 16.04 VM boots up, but I find that inserting a sleep 10 into a task is required to reliably be able to apt-get install some packages.

[seibert]

My speculation based on googling for similar issues is that some auto-updater in Ubuntu is enabled, and it tries to refresh the package index when the VM starts up.

[chrispat]

@seibert yes we found a systemd unit that was running as soon as the network came up that was updating the apt cache. Due to the way we pool machines some sit for longer before they take a job and that is why you see the intermittent failure. We are working on a fix, thanks for the pointer to help narrow this down.

[seibert]

Great! Glad you were able to figure out the issue.

[stuartarchibald]

Thanks for the patch, seems to mitigate the issue noted. Merging.