If there is an error in the execution of a powershell command, the error is lost

[manuelbuil]

I am currently trying flannel on windows and forgot to give a correct $PATH to reach powershell.exe. The error I am getting in the logs is an empty string which provides no information. The reason for this is that this function: https://github.com/flannel-io/flannel/blob/master/pkg/powershell/powershell.go#L34 ig nores the error of cmd.Output() if cmd.ProcessState.ExitCode() != 0

Expected Behavior

We get a useful log that explain what is going on

Current Behavior

This is the log we get:

E0110 06:08:53.485895    3408 main.go:276] Failed to find any valid interface to use: failed to get default interface:

which is useless

Possible Solution

Steps to Reproduce (for bugs)

Context

Your Environment

• Flannel version:
• Backend used (e.g. vxlan or udp):
• Etcd version:
• Kubernetes version (if used):
• Operating System and version:
• Link to your project (optional):