Error when loading vega-lite example data sets

[rieser]

Edit: Part (2) of this issue is also found at Lisp-Stat/plot#19 (comment). The first part occurs after loading cl-date-time-parser in SBCL on Ubuntu 22.04.

(1) When I load the vega-lite data sets using

(vega:load-vega-examples)

I get the following error:

Could not REQUIRE CL-DATE-TIME-PARSER: circularity detected. Please check your configuration
`
However, the examples appear to have loaded.

(2) Also, before I installed cl-date-time-parser in quicklisp, I was getting an error message similar to:

Do not know how to REQUIRE CL-DATE-TIME-PARSER