The infamous build error when cross-compiling to QNX on Windows with "g++" not being in the PATH happens significantly more often under the kvm virtualization than under vSphere.
We do know that this is a race-condition somewhere. But unfortunately we don't know what aspect of the system triggers it. In this scenario we are using a different hypervisor (qemu/kvm), different physical hardware and a different storage layer.
This is important to the OpenNebula transition project as this being present will cause a lot more "stage again" type of situations as today.