If $HOME is unset, consult (user-info (user-uid)) for the value of home-directory.

scsh/scsh.scm

@@ -963,10 +963,20 @@
 
 (define (init-scsh-vars quietly?)
   (set! home-directory
-	(cond ((getenv "HOME") => ensure-file-name-is-nondirectory)
-	      (else (if (not quietly?)
-			(warn "Starting up with no home directory ($HOME)."))
-		    "/")))
+ 	(cond ((getenv "HOME") => ensure-file-name-is-nondirectory)
+	      ;; loosing at this point would be really bad, so some
+	      ;; paranoia comes in order
+ 	      (else (call-with-current-continuation 
+		     (lambda (k)
+		       (with-handler
+			(lambda (condition more)
+			  (cond ((not quietly?)
+				 (display "Starting up with no home directory ($HOME).")
+				 (newline)))
+			  (k "/"))
+			(lambda ()
+			  (user-info:home-dir (user-info (user-uid))))))))))
+	      
   (set-fluid! exec-path-list
 	      (cond ((getenv "PATH") => split-colon-list)
 		    (else (if (not quietly?)