Tracking issue for CommandExt::before_exec

[alexcrichton]

Open questions:

• The requirements for Send + Sync on the closure need to be documented and are "somewhat odd"
• It's somewhat surprising to have to deal with a list of callbacks to invoke, especially when order might matter quite a bit.
• There are weird semantics with using Stdio::piped() for any of the stdio handles because they'll immediately close the other half of the pipe (via CLOEXEC).

This is a tracking issue for rust-lang/rfcs#1359.

[dirk]

I'm planning on giving this a shot this evening. 😄

[alexcrichton]

@dirk oh sorry I should have mentioned that I'm working on implementing this. There's actually a good deal of refactoring I'd like to do at the same time, and I'm already halfway through it so far!

[dirk]

@alexcrichton: Oh, no worries! Thanks for replying so quickly.