Add new package gnuconfig (#25849)

var/spack/repos/builtin/packages/gnuconfig/package.py

@@ -0,0 +1,26 @@
+# Copyright 2013-2021 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class Gnuconfig(Package):
+    """
+    The GNU config.guess and config.sub scripts versioned by timestamp.
+    This package can be used as a build dependency for autotools packages that
+    ship a tarball with outdated config.guess and config.sub files.
+    """
+
+    homepage = "https://www.gnu.org/software/config/"
+    url      = "https://github.com/haampie/config/archive/refs/tags/2021-08-14.tar.gz"
+
+    maintainers = ['haampie']
+
+    version('2021-08-14', sha256='1d1134f2f9d5f1342693793a536643c9aa11eaf672d1bf453ce2a415fdb8ebcc')
+
+    def install(self, spec, prefix):
+        with working_dir(self.stage.source_path):
+            install('config.sub', prefix)
+            install('config.guess', prefix)