My workflow when it comes to development on lisp libraries, is to change into the project the launch a SLIME shell. This works great but how do I load systems from that project?

Well I used to use a snippet like this.

(push (truename (make-pathname :directory (sb-posix:getcwd)))
      asdf:*central-registry*)

This is not what most people seem to be doing, instead they are using a local projects directory to host any local projects for example in roswell that directory is .roswell/local-projects. But often I find that I might want to try and extend a system, or to hack on it, so I like to have local copies.

I had experimented with creating symlinks into the local project dir, but in the end it has always left me unsatusfied.

While looking into better ways to do this I found that the asdf:*central-registry* is not recommended as the way to add paths to the load order. Instead it's recomeneded that you add configuration files to .config/common-lisp/source-registry.conf.d that will state where to find systems.

It does have one limitation though, you can't exceute anything, the files are loaded and treated as data.

But through some experimentation I found that read macros are honored, so doing something like this will always add the current working directory of any lisp to the load path. Just insert it into .config/common-lisp/source-registry.conf.d/pwd.conf.

;;; -*- Mode: Lisp; Syntax: COMMON-LISP; Base: 10 -*-
(:directory #.(uiop/os:getcwd))