dot/lisp-init.lisp: Don't set SBCL source directory if there's no source there.

diff --git a/dot/lisp-init.lisp b/dot/lisp-init.lisp
index 64faf2bdb0fe24c790012115914d4f7fbff3c37a..91971ca619c21baf9964650807f81c2448057781 100644 (file)
--- a/dot/lisp-init.lisp
+++ b/dot/lisp-init.lisp
@@ -48,7 +48,9 @@ (setf ccl:*quit-on-eof* t)
 
 ;; Tell SBCL where to find its source source.
 #+sbcl
-(sb-ext:set-sbcl-source-location #p"/usr/share/sbcl-source/")
+(let ((srcdir #p"/usr/share/sbcl-source/"))
+  (when (probe-file srcdir)
+    (sb-ext:set-sbcl-source-location srcdir)))
 
 ;; Get SBCL to shut up about package variance.  This is a standard result of
 ;; my approach to symbol exports, and I don't care.