Panic when post-test.sh fails

[guillaumerose]

Having a failure in post-test.sh involved a panic.

panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0x20 pc=0x537ca8]

goroutine 1 [running]:
github.com/linuxkit/rtf/local.(*Test).Run(0xc0421456c0, 0x1, 0x862cd4, 0x5, 0xc0421b3c00, 0x65, 0xa74520, 0xc042002e20, 0x86204d, 0x3, ...)
	C:/Users/docker/go/src/github.com/linuxkit/rtf/local/test.go:154 +0xa58
github.com/linuxkit/rtf/local.(*Group).Run(0xc04211fab0, 0x1, 0x862cd4, 0x5, 0xc0421b3c00, 0x65, 0xa74520, 0xc042002e20, 0x86204d, 0x3, ...)

I suspect this return : https://github.com/linuxkit/rtf/blob/master/local/script.go#L143
res.TestResult can be different than Pass and have nil error.