Since a GNUmakefile wrapper has been introduced in our build
system, a "make" invocation issued before a "./configure" one
has caused GNU make to die with the cryptic message:
GNUmakefile:18: Makefile: No such file or directory
GNUmakefile:19: /syntax-checks.mk: No such file or directory
make: *** No rule to make target `/syntax-checks.mk'. Stop.
* GNUmakefile: Detect when we are being run from an unconfigured
tree, and give helpful diagnostic.
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
-include ./Makefile
-include $(srcdir)/syntax-checks.mk
+# If the user runs GNU make but has not yet run ./configure,
+# give them an helpful diagnostic instead of a cryptic error.
+am--Makefile := $(wildcard Makefile)
+ifeq ($(am--Makefile),)
+ $(warning There seems to be no Makefile in this directory.)
+ $(warning You must run ./configure before running 'make'.)
+ $(error Fatal Error)
+else
+ include ./Makefile
+ include $(srcdir)/syntax-checks.mk
+endif