Interactive mode

[JosuGZ]

Checklist

• I've looked through the issues and pull requests for similar request

Describe your request

I would like to be able to run the containers on interactive mode.

Describe why this would be a good inclusion for cross

This could be useful to troubleshot build problems. For instance, right now git describe is not working on some of my targets.

I can of course do that by hand, but getting a terminal into the containers could be interesting. Something like cross interactive --target foo.

[Alexhuszagh]

This wouldn't be in cross due the need for complete API compatibility (so any CLI flags should be processed identical by cargo and cross), but could be used for cross-util. The downside is the implementation is a bit non-trivial, since we'd:

• Need to process all the package and config data
• Parse the command line options
• If using remote, do everything like that
• Add an interactive mode to add the -i flag
• Change it to use bash or sh for interactive mode (likely would require sh since with custom containers we can't guarantee the presence of bash).

All of this is doable, just most of it isn't currently exposed to cross-util without some refactoring.

[Alexhuszagh]

We could have a cross-util cargo subcommands or similar which would process the command-line flags but also allow custom cross extensions.

[kingosticks]

Won't #1280 allow you to now do this? I'm using it to debug and run cargo-deb.

[Emilgardis]

You'd be correct @kingosticks, thanks! We also have #716 which is a bit more specific but not solved with #1280