Process / NSTask

[iCharlesHu]

We need to reimagine what Process should look like in Swift. Most likely we will introduce a new type.

rdar://118127512

[Frizlab]

FWIW, I did some work on launching a Process in Swift. It’s probably not what I’d want in Foundation as-is, but it can give some ideas.

https://github.com/xcode-actions/XcodeTools/blob/main/Sources/XcodeTools/Process/ProcessInvocation.swift

On the top of my head, my main pain points were (unordered):

• No possibilities of sending file descriptors to the child;
• No easy streaming of process output (bonus, w/ fd differentiation);
• PGID is different on child process (and there is no option to change that);
• Process does not search for the executable in PATH for non-absolute paths.

There are other problems with the current API of course, but they are more obvious.

[compnerd]

I think that one thing that I would like to bring up while this is early in the process - Windows likes to throw a stupid wrench into this :(. The environment control block should be case insensitive. This is particularly important for Path (vs PATH) and any possible case variant which should be treated equivalently.

[iCharlesHu]

Pitch is up: #397