[RFC PATCH] Makefile: point out "make" if "make configure" fails

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Someone trying to build Git may think the need autoconf when "make
configure && ./configure && make" fails. But actually they can
probably just run "make" directly.

Change the "make configure" output so that when it fails the user is
informed of this:

    make configure && ./configure && make
        GEN configure
    ERROR: We couldn't run autoconf for you. But you're in luck!
    ERROR: Git doesn't actually need autoconf to build. Just try
    ERROR: running "make" directly at the top-level. The Makefile
    ERROR: will guess your configuration based on your OS. If that
    ERROR: doesn't work try installing autoconf and running
    ERROR: "make configure && ./configure && make" again.
    make: *** [configure] Error 1

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---

On Mon, Oct 11, 2010 at 12:10, Michael J Gruber <git@drmicha.warpmail.net> wrote:
> Ævar Arnfjörð Bjarmason venit, vidit, dixit 11.10.2010 11:40:
>> On Mon, Oct 11, 2010 at 08:39, Jakub Narebski <jnareb@gmail.com> wrote:
>>
>>> But thanks to having ./configure optional step, we can build git also
>>> on platforms that doesn't have autoconf installed (though the same could
>>> be achieved by bundling ./configure script with release tarballs).
>>
>> It already is built as part of the tarballs, at least for
>> http://kernel.org/pub/software/scm/git/git-1.7.3.1.tar.bz2
>
> Well, the point of my semi-serious RFC is that every so often, we have a
> variation on the following theme on the list:
>
> - "Newbee" uses make configure && ./configure && make and can't build.
> - Helpful "oldbees" respond like "Duh! Use the Makefile".
>
> configure is a second class citizen in git.git (we even explicitly
> .gitignore it - if you allow that lame joke), and given my complete lack
> of auto-conf-foo, I can't change that. But there's no need to make
> someone feel stupid (I'm exaggerating a bit) for trying a standard build
> tool that we do ship.
>
> But, really, the typical responses to build problems with configure
> indicate that most long timers don't use configure either, and probably
> don't feel too comfortable with it. So, I think we should either make
> the status quo clearer (Makefile as primary method) or change the status
> quo. I can only do the former ;)

The main problem with your patch is that existing invocations of "make
configure" have to be altered. I haven't scoured the mailing list for
these newbie reports you mention but aren't they mostly failing
because users don't have autoconf installed, and not because the
configure script itself fails?

If that's case something like this patch would probably be better, and
maybe we also need to change something in the INSTALL file or other
documentation.

 Makefile |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index 1f1ce04..6d2928d 100644
--- a/Makefile
+++ b/Makefile
@@ -1747,7 +1747,16 @@ configure: configure.ac
 	$(QUIET_GEN)$(RM) $@ $<+ && \
 	sed -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \
 	    $< > $<+ && \
-	autoconf -o $@ $<+ && \
+	if ! autoconf -o $@ $<+; \
+	then \
+		echo "ERROR: We couldn't run autoconf for you. But you're in luck!"; \
+		echo "ERROR: Git doesn't actually need autoconf to build. Just try"; \
+		echo "ERROR: running \"make\" directly at the top-level. The Makefile"; \
+		echo "ERROR: will guess your configuration based on your OS. If that"; \
+		echo "ERROR: doesn't work try installing autoconf and running"; \
+		echo "ERROR: \"make configure && ./configure && make\" again."; \
+		false; \
+	fi && \
 	$(RM) $<+
 
 # These can record GIT_VERSION
-- 
1.7.3.1.50.g1e633