Try to fix mixed console output on Windows

[pplu]

When executing carton exec COMMAND on Windows, the command returns to
the command prompt while it's running. Using system instead of exec on Windows makes carton behave correctly

[pplu]

Any thoughts on this changeset? It really helps windows users

[tynovsky]

Any progress with this merge request? I am also suffering from this issue, trying to run carton exec ... in Teamcity and as it forks/exec, Teamcity thinks the process ended immediately after start.

[pplu]

Hi

@miyagawa Would you reconsider the patch in 1331aac for carton? It really helps carton exec behave the same way under Windows and Linux, and as @tynovsky reports, it seems I'm not alone.

I'm maintaining a mini-fork of carton for our use into which I have merged some outstanding PRs that we needed (that's why you see more commits on this PR). Only 1331aac solves the "mixed output" problem.

@miyagawa: I know you are dedicating time to Carmel. Do you think I can help you get some carton work done?

[miyagawa]

cherry-picked 1331aac

I think win32 users would better skip carton exec and do use lib local/lib/perl5 though.

[miyagawa]

I reverted the cherry-picked patch above, and instead added carton run which doesn't invoke exec. That way, carton exec will always be exec regardless of platforms.