[src/trunk]: src/usr.bin/make/unit-tests tests/make: document why deptgt-posi...

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

details:   https://anonhg.NetBSD.org/src/rev/efa8026f5ee8
branches:  trunk
changeset: 365994:efa8026f5ee8
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat May 07 21:24:52 2022 +0000

description:
tests/make: document why deptgt-posix needs its own directory

As described in PR toolchain/15163, '.include <file>' first looks in the
current directory, using the system include path only as fallback.

diffstat:

 usr.bin/make/unit-tests/deptgt-posix.mk |  7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diffs (21 lines):

diff -r 2f8196ae8e17 -r efa8026f5ee8 usr.bin/make/unit-tests/deptgt-posix.mk
--- a/usr.bin/make/unit-tests/deptgt-posix.mk   Sat May 07 21:19:43 2022 +0000
+++ b/usr.bin/make/unit-tests/deptgt-posix.mk   Sat May 07 21:24:52 2022 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: deptgt-posix.mk,v 1.3 2022/05/07 12:40:40 rillig Exp $
+# $NetBSD: deptgt-posix.mk,v 1.4 2022/05/07 21:24:52 rillig Exp $
 #
 # Tests for the special target '.POSIX', which enables POSIX mode.
 #
@@ -13,7 +13,10 @@
 #
 # Implementation note: this test needs to run isolated from the usual tests
 # directory to prevent unit-tests/posix.mk from interfering with the posix.mk
-# from the system directory that this test uses.
+# from the system directory that this test uses; since at least 1997, the
+# directive '.include <file>' has been looking in the current directory first
+# before searching the file in the system search path, as described in
+# https://gnats.netbsd.org/15163.
 #
 # See also:
 #      https://pubs.opengroup.org/onlinepubs/9699919799/utilities/make.html