[pkgsrc/trunk]: pkgsrc/mk/misc Documented the trap into which I had just fallen.

[rillig <rillig%pkgsrc.org@localhost>]

details:   https://anonhg.NetBSD.org/pkgsrc/rev/64e9e2c722e7
branches:  trunk
changeset: 396600:64e9e2c722e7
user:      rillig <rillig%pkgsrc.org@localhost>
date:      Tue Jul 28 07:01:56 2009 +0000

description:
Documented the trap into which I had just fallen.

diffstat:

 mk/misc/show.mk |  9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diffs (23 lines):

diff -r 2198017772e1 -r 64e9e2c722e7 mk/misc/show.mk
--- a/mk/misc/show.mk   Tue Jul 28 06:55:24 2009 +0000
+++ b/mk/misc/show.mk   Tue Jul 28 07:01:56 2009 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: show.mk,v 1.9 2008/11/19 08:06:36 rillig Exp $
+# $NetBSD: show.mk,v 1.10 2009/07/28 07:01:56 rillig Exp $
 #
 # This file contains some targets that print information gathered from
 # variables. They do not modify any variables.
@@ -88,6 +88,13 @@
 #              * "pkg" for package-settable variables,
 #              * "sys" for system-defined variables.
 #
+#      CAVEAT: Some few variable values that are shown here may be
+#      misleading. For example, make(1)'s := operator leaves references
+#      to undefined variables as-is, so they may be resolved later. So
+#      if you want to take a snapshot of the exact value of a variable,
+#      you have to use "snapshot!=printf %s ''${var:q}" instead of
+#      "snapshot:=${var}".
+#
 # Keywords: debug show _vargroups
 #