Incomplete application logs when using -appcmd

[jalaziz]

While testing nitriding with -appcmd, I noticed the the application logs were inconsistent on every run (even though the application was failing for the same reason each run). If an application dies quickly, it appears that nitriding can exit before all the application logs are printed.

Looking at the source code, I believe this may because stdout and stderr and streamed via a goroutine, but the routines are not waited on before nitriding exits.

[rillian]

Sounds plausible.