"optional" subdir()?

[nils-werner]

Is there a way to implement an optional/not-required subdir()?

I would like to provide my team with a .gitignored directory, like workbench/, where they can put short-lived code-experiments that interact with our codebase, but shouldn't permanently or accidentally end up in Git.

[nils-werner]

The more I thought about this the less I liked the "magic but unexpected behaviour", so I've decided making this a conscious choice by putting a parameter enable_workbench in meson_options.txt.

[eli-schwartz]

You could use:

fs_mod = import('fs')

if fs.exists('optional/meson.build')
    subdir('optional')
endif

Note that adding that subdir will not trigger a meson reconfigure so if users do that then they'll need to also manually reconfigure. Removing it, however, will trigger reconfiguration.