use macro for /usr/local/plan9
diff --git a/man/man3/getcallerpc.3 b/man/man3/getcallerpc.3
index 8ad95a3..4815bc9 100644
--- a/man/man3/getcallerpc.3
+++ b/man/man3/getcallerpc.3
@@ -31,7 +31,7 @@
 }
 .EE
 .SH SOURCE
-.B /usr/local/plan9/src/lib9/
+.B \*9/src/lib9/
 .SH BUGS
 The 
 .I firstarg