log4cl

Not sure if either of the linked issues below are from you, but it looks like the referenced file in Log4CL references internal SBCL symbols which are liable to change in versions. Last I heard, the M1 build of SBCL was a bit unique, so it might be worth opening an issue there. The sharplispers fork is the maintained one, I believe. https://github.com/7max/log4cl/issues/41 https://github.com/sharplispers/log4cl/issues/45

Things are changing, but some problems remain the same. Right now, you have a pretty solid logging library in CL that is pretty much the go-to for anything but simplest of needs: log4cl[0]. It's feature-rich, performant, and even integrates with Emacs/SLIME. The README covers a lot of those things... briefly. Good luck figuring out how to e.g. use the (log:config) facility for anything more complicated than changing log levels. As you can see[1], it has a huge docstring describing a lot of things, but the description is shallow. It's like 20% of what is needed to figure out common things like just saving output to a fresh file (without automatic log rotation). This is IMO a good example of the problem I see in those libraries that are actually solid and done. They miss detailed user-oriented documentation, forcing you to wade through code

In [Successful Lisp, how to understand and use CL](http://www.communitypicks.com/r/lisp/s/17592186045679-succes...) there is a chapter on debugging. Book's site, free dl: https://successful-lisp.blogspot.com Also, it may not be necessary to master the most complicated machinery: compiling function by function gives lots of hints, and the very nice [log4cl](https://github.com/sharplispers/log4cl/) is handy.