Archiving because I discovered https://github.com/stevearc/overseer.nvim, which seems to do this already.

buildit.nvim

An async project builder for Neovim. Compatible with (but not reliant on) VS Code-style tasks.json specifications.

Why would I use this?

buildit does a good job of automatically detecting the correct builder to use for a given buffer, and runs said builder in a new process, asynchronously. Further, it does not interfere with your working directory, and it can handle several simultaneous builds.

What this boils down to is that you can very easily trigger builds for several subprojects, have them work correctly without having to fiddle around with configuration, and keep editing uninterrupted.

For more, see the FAQ or the docs

Installation

Use your favorite plugin manager.

With packer.nvim:

use {'wbthomason/buildit.nvim', requires = 'nvim-lua/plenary.nvim'}

Usage

TODO rewrite for Lua rewrite of plugin.