Index: common.scm
==================================================================
--- common.scm
+++ common.scm
@@ -186,11 +186,23 @@
 ;; Miscellaneous
 (define *triggers-mutex*     (make-mutex))     ;; block overlapping processing of triggers
 
 (use posix-extras pathname-expand files)
 
-(define ##sys#expand-home-path pathname-expand) ;; plugs a hole in posix-extras in recent chicken versions
+;; this plugs a hole in posix-extras in recent chicken versions > 4.9)
+(let-values (( (chicken-release-number chicken-major-version)
+               (apply values
+                      (map string->number
+                           (take
+                            (string-split (chicken-version) ".")
+                            2)))))
+  (let ((resolve-pathname-broken?
+         (or (> chicken-release-number 4)
+             (and (eq? 4 chicken-release-number) (> chicken-major-version 9)))))
+    (if resolve-pathname-broken?
+        (define ##sys#expand-home-path pathname-expand))))
+      
 (define (realpath x) (resolve-pathname  (pathname-expand (or x "/dev/null")) ))
 
 (define (common:get-this-exe-fullpath #!key (argv (argv)))
   (let* ((this-script
           (cond