x/crypto/ssh: Return better error message for non-zero exit codes

[variadico]

Version
go version go1.5.3 darwin/amd64

What I did
I executed a script on a remote server through SSH.

if err := sesh.Run("/home/jaime/fail.sh"); err != nil {
    log.Println(err)
}

This is fail.sh.

#!/bin/sh
exit 1

What I expected to see
I expected to see a clear and concise error. Maybe something like: Process exited with: 1.

What I saw instead
I saw a slightly confusing and half-useless error: Process exited with: 1. Reason was: ()

The code in question is here, crypto/ssh/session.go:604. This is happening because it's Sprintfing empty w.msg and w.signal values. This doesn't seem right.

[davecheney]

We could slop the printing of the Reason was: () part if w.msg is blank.

[variadico]

Sounds reasonable. I'm willing to submit a PR, if possible.

[gopherbot]

CL https://golang.org/cl/19444 mentions this issue.

[sctb]

@variadico Are you still working on this one, or is it free to pick up?

[variadico]

I never heard back from anyone, so I never started. But, it looks like someone else grabbed this already: https://go-review.googlesource.com/#/c/19444. The status says "Needs Code-Review".

[gopherbot]

CL https://golang.org/cl/22196 mentions this issue.

[udayskyport]

@gopherbot
I am still facing the issue where session.Run() returns --> Process exited with: 1. Reason was: ()
if the scp path is incorrect.
Can you please help?

[ianlancetaylor]

@udayskyport Which version of Go are you using?

[udayskyport]

@ianlancetaylor go1.6