SLY contrib that adds support for editing ASDF systems.
Ported from slime with changes to support
package-inferred-system. Potentially I'd like to make some future changes to improve debugging ASDF systems (e.g., cut off stack trace at system boundaries, etc.)
Now available from MELPA
Installing manually will require the contrib be registered in SLY's
(add-to-list 'sly-contribs 'sly-asdf 'append)