Handle failures when running NuGet (exitCode != 0, output to stderr)

[webcoyote]

Previously the script Run-NuGet.ps1 ignored the process exit code so that errors were not propagated to the caller.

This change throws an error when either the process exits with a non-zero value or if errors are written to stderr, which makes Chocolatey more suitable for being called from other scripts.

For example, I'm using Chocolatey to install and build a Linux virtual machine on Windows with a single PowerShell command (https://github.com/webcoyote/linux-vm). Chocolatey is awesome for projects like this!

[rismoney]

had you seen #210? I tried to deal with process exits throughout all of chocolatey.

btw- linux-vm looks really really awesome.

[webcoyote]

I looked at #210 before I submitted my pull request; I was hoping that it already included
the change that I needed. In my (uncommitted) changes on my linux-vm project I skipped over all the batch files and called directly into chocolatey.ps1 exactly because the batch files didn't propagate errors, so I'm glad you fixed that. I did note that it was two months back that your changes were made; I hope they get merged.

I am a bit conflicted about my solution, which uses "throw". It doesn't create a very nice error for end-users, but it's great for developers. Hopefully someone will provide clarity on how errors should be handled, because I was waffling between "throw" and "write-host & exit".

And thanks for your comments on linux-vm. A bit more error checking and I will be happy with it! Let me know if you have any comments on the project -- I'm glad to do fixes :)

[rismoney]

I completely relate. My main concern was to always exit 1 if there was a failure on any of the functions. I recently delved into puppet/ruby so my main concern was to never return an exit 0 if something went wrong which is the current behavior. It's funny, when I use chocolatey interactively i never use the batch files. when i use it programmatically via puppet i used the bat files. its because i never use cmd, so its silly for me to call a batch to call powershell if i am already in it.

unrelated, but calling posh from ruby strangely irks me with powershell.exe, maybe for the opposite reason. If I can run an exec, and call the bat, then i avoid the powershell.exe

I haven't found a great method to interact with powershell via ruby, particularly for multi-line code blocks.

[ferventcoder]

I believe at some point when nuget was throwing non-zero exit codes for any exit, so it was unreliable to be used in that manner. I think they may have fixed this in more recent versions.