--vt N option seems to be unreliable/racing

[Daniel van Vugt]

This command: sudo bin/mir_demo_server_shell --vt 1

Sometimes fails with:
ERROR: /home/dan/bzr/mir/toy/src/server/graphics/gbm/gbm_display_helpers.cpp(159): Throw in function int mir::graphics::gbm::helpers::DRMHelper::open_drm_device()
Dynamic exception type: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<std::runtime_error> >
std::exception::what: Problem opening DRM device
[boost::errinfo_errno_*] = 1, "Operation not permitted"

It does correctly switch to VT 1. But fails to start as you see above.

Running the same command a second time works. Which makes it look like a race -- we're not waiting for the VT switch to complete before opening the device. Or more likely, not waiting for X (VT7) to relinquish the DRM device before trying to grab it.

[Daniel van Vugt (vanvugt)]

This appears to have been fixed. Looks like from:
lp:~thomas-voss/mir/wait-for-vt-to-become-active-before-setting-mode