#6584 feat: add --exec option

[Anonymous]

Originally created by: orisano

i implemented --exec option on docker-compose build for to use buildkit.

This PR is prototype. please give me feedback.

[Anonymous]

Originally posted by: GordonTheTurtle

Please sign your commits following these rules:
https://github.com/moby/moby/blob/master/CONTRIBUTING.md#sign-your-work
The easiest way to do this is to amend the last commit:

$ git clone -b "feat-add-exec-build" git@github.com:orisano/compose.git somewhere
$ cd somewhere
$ git commit --amend -s --no-edit
$ git push -f

Amending updates the existing PR. You DO NOT need to open a new one.

[Anonymous]

Originally posted by: AkihiroSuda

cc @tonistiigi @tiborvass