Quoth Sebastian Tennant sebyte@smolny.plus.com:

Mine is a standard sbcl installation ($ ./install.sh) yet I can only get this speed-up to work if I provide an absolute path to the core:

("sbcl" "--core" "/usr/local/lib/sbcl/sbcl.core-with-swank")

What am I missing?

Just came across this in sbcl's INSTALL file:

1.2. Finding ancillary files

The SBCL runtime needs to be able to find the ancillary files associated with it: the "sbcl.core" file, and the contrib modules.

Finding core can happen in three ways:

1. By default, in a location configured when the system was built. For binary distributions this is in "/usr/local/lib/sbcl".

2. By environment variable, in the directory named by the environment variable "SBCL_HOME". Example:

$ export SBCL_HOME=/foo/bar/lib/sbcl $ sbcl

If your "INSTALL_ROOT" was FOO, then your "SBCL_HOME" is "FOO/lib/sbcl".

3. By command line option:

$ sbcl --core /foo/bar/sbcl.core

This suggests that when the --core command-line option is used, an absolute path is precisely what is needed, and the fact that I can't get the inferior lisp process to run without specifying an absolute path (despite the fact my sbcl.core-with-swank is in the 'default location') pretty much seals it for me.

The Slime manual suggests otherwise though (info "(slime) Loading Swank faster"):

Then add this to your `.emacs':

(setq slime-lisp-implementations '((sbcl ("sbcl" "--core" "sbcl.core-with-swank") :init (lambda (port-file _) (format "(swank:start-server %S)\n" port-file)))))

Could someone clarify this situation?

Sebastian