package/tar: allowing building even on non-Y2038 compliant systems

Since the bump of tar to version 1.35 in Buildroot commit
d4d483451f0a305781b94b96c15a6cf4b489cd84 ("package/tar: security bump
to version 1.35"), the build will fail on systems that are not Y2038,
such as uClibc configurations.

In order to preserve the previous behavior, pass --disable-year2038.
See the gnulib documentation for details [0]. Contrary to what the
option name might suggest, it doesn't really disable Y2038 support,
but only the check that the system is Y2038 compliant. So even with
--disable-year2038, if the system is Y2038 compliant (uses a 64-bit
arch, uses the musl C library, or uses the glibc C library with
BR2_TIME_BITS_64=y), tar will be Y2038 compliant.

[0] https://www.gnu.org/software/gnulib/manual/html_node/Avoiding-the-year-2038-problem.html

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/tar/tar.mk

@@ -7,9 +7,15 @@
 TAR_VERSION = 1.35
 TAR_SOURCE = tar-$(TAR_VERSION).tar.xz
 TAR_SITE = $(BR2_GNU_MIRROR)/tar
-# busybox installs in /bin, so we need tar to install as well in /bin
-# so that we don't end up with two different tar
-TAR_CONF_OPTS = --exec-prefix=/
+# --exec-prefix=/: busybox installs in /bin, so we need tar to install
+# as well in /bin so that we don't end up with two different tar
+#
+# --disable-year2038: tells the configure script to not abort if the
+# system is not Y2038 compliant. tar will support year2038 if the
+# system is compliant even with this option passed
+TAR_CONF_OPTS = \
+	--exec-prefix=/ \
+	--disable-year2038
 TAR_LICENSE = GPL-3.0+
 TAR_LICENSE_FILES = COPYING
 TAR_CPE_ID_VENDOR = gnu