[RFC PATCH] Makefile: Turn off the configure target by default

[RFC PATCH] Makefile: Turn off the configure target by default

[Michael J Gruber]

For most software packages, untar-autoconf/make configure-configure-make
is the preferred way to build the package; not so for Git. But the
presence of the make target makes people believe so.

Try and make people use "make configure" only when they are sure they
need to.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
---
    This does not help with people running autoconf themselves, of course.
    But we keep answering questions about failed configure attempts.
    
    On an annecdotical note: When I decided to switch to a dvcs, I failed building
    Git (with configure) and tried out hg instead. Imagine!

 Makefile |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/Makefile b/Makefile
index 1f1ce04..430c096 100644
--- a/Makefile
+++ b/Makefile
@@ -1744,11 +1744,18 @@ $(patsubst %.py,%,$(SCRIPT_PYTHON)): % : unimplemented.sh
 endif # NO_PYTHON
 
 configure: configure.ac
+ifdef USEAUTOCONF
 	$(QUIET_GEN)$(RM) $@ $<+ && \
 	sed -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \
 	    $< > $<+ && \
 	autoconf -o $@ $<+ && \
 	$(RM) $<+
+else
+	@echo "Using the Makefile and defining variables in config.mak is the"
+	@echo "preferred way of building Git. Please use"
+	@echo "USEAUTOCONF=1 make configure"
+	@echo "if you are really sure you need configure."
+endif
 
 # These can record GIT_VERSION
 git.o git.spec \
-- 
1.7.3.1.184.g5b1fd

Re: [RFC PATCH] Makefile: Turn off the configure target by default

[Ævar Arnfjörð Bjarmason]

On Mon, Oct 11, 2010 at 07:47, Michael J Gruber
<git@drmicha.warpmail.net> wrote:

(CC-ing Jakub Narebski, who maintains configure.ac)

I don't like it. For one this would break build scripts that use `make
configure && ./configure && ...`. It's also annoying to have to set
some variable to *really* invoke a target that I just indicated I
*really* wanted by invoking it in the first place.

Perhaps a @echo from the configure script itself indicating that it's
complimentary would be better.

> For most software packages, untar-autoconf/make configure-configure-make
> is the preferred way to build the package; not so for Git. But the
> presence of the make target makes people believe so.

Unlike in most packages autoconf is strictly complimentary for Git,
but it usually gives you much better results. Instead of the Makefile
guessing based on `uname -s` we actually check for features and set
the config.mak.autogen variables accordingly.

So it's less likely to break on odd systems, and given that (as you
point out) mostly everyone has autoconf already recommending it as the
default would make more sense than the other way around.

>    On an annecdotical note: When I decided to switch to a dvcs, I failed building
>    Git (with configure) and tried out hg instead. Imagine!

What sort of failure? Has it been fixed since then?

Re: [RFC PATCH] Makefile: Turn off the configure target by default

[Jakub Narebski]

On Mon, 11 Oct 2010, Ævar Arnfjörð Bjarmason wrote:
> On Mon, Oct 11, 2010 at 07:47, Michael J Gruber
> <git@drmicha.warpmail.net> wrote:
> 
> (CC-ing Jakub Narebski, who maintains configure.ac)

I wouldn't say that I maintain it.  I was one of people who started it,
and I try to keep it from being too bitrotten, by asking to provide
configure test when adding new configure knob to main Makefile.

I am certainly not an expert on autoconf.

> I don't like it. For one this would break build scripts that use `make
> configure && ./configure && ...`. It's also annoying to have to set
> some variable to *really* invoke a target that I just indicated I
> *really* wanted by invoking it in the first place.
> 
> Perhaps a @echo from the configure script itself indicating that it's
> complimentary would be better.
> 
> > For most software packages, untar-autoconf/make configure-configure-make
> > is the preferred way to build the package; not so for Git. But the
> > presence of the make target makes people believe so.
> 
> Unlike in most packages autoconf is strictly complimentary for Git,
> but it usually gives you much better results. Instead of the Makefile
> guessing based on `uname -s` we actually check for features and set
> the config.mak.autogen variables accordingly.

That's why we have it, to be able to check for features, rather than
guess based on operating system and its version.
 
> So it's less likely to break on odd systems, and given that (as you
> point out) mostly everyone has autoconf already recommending it as the
> default would make more sense than the other way around.

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).

> >    On an annecdotical note: When I decided to switch to a dvcs, I failed building
> >    Git (with configure) and tried out hg instead. Imagine!
> 
> What sort of failure? Has it been fixed since then?


-- 
Jakub Narebski
Poland

Re: [RFC PATCH] Makefile: Turn off the configure target by default

[Ævar Arnfjörð Bjarmason]

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

Re: [RFC PATCH] Makefile: Turn off the configure target by default

[Michael J Gruber]

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 ;)

Michael

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

[Ævar Arnfjörð Bjarmason]

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

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

[Jakub Narebski]

On Mon, 11 Oct 2010, Ævar Arnfjörð Bjarmason wrote:

> 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>

I like this.

-- 
Jakub Narebski
Poland

Re: [RFC PATCH] Makefile: Turn off the configure target by default

[Jakub Narebski]

Dnia poniedziałek 11. października 2010 14:10, Michael J Gruber napisał:
> 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.

As Ævar writes this happen mostly because "newbee" doesn't have autoconf
installed (and is not using released tarball, where ./configure script
is included).  Ævar solution is much better.

> - Helpful "oldbees" respond like "Duh! Use the Makefile".

This can happen because A.) "oldbee" doesn't use configure script
himself, so he gives (universal) advice that he can check, or B.) 
because there is an error in both Makefile guessing and ./configure
script doesn't detect or misdetect thing; then "Use the Makefile"
can be considered workaround for the issue till bug gets fixed.

> configure is a second class citizen in git.git (we even explicitly
> .gitignore it - if you allow that lame joke),

We .gitignore 'configure' script because it is *generated* file, and
generated files should be not, as rule, placed under version control.

> 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 ;)

Because ./configure script enhances Makefile rather than generate it,
using configure script can only improve situation (at the cost of extra
cycles spent detecting)... well, with exception of rare cases bugs in
configure.ac making it misdetect.

-- 
Jakub Narebski
Poland

Re: [RFC PATCH] Makefile: Turn off the configure target by default

[Michael J Gruber]

Jakub Narebski venit, vidit, dixit 11.10.2010 17:18:
> Dnia poniedziałek 11. października 2010 14:10, Michael J Gruber napisał:
>> 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:
>>>
...
>> configure is a second class citizen in git.git (we even explicitly
>> .gitignore it - if you allow that lame joke),
> 
> We .gitignore 'configure' script because it is *generated* file, and
> generated files should be not, as rule, placed under version control.

I don't know which part of "joke" was unclear?

> 
>> 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 ;)
> 
> Because ./configure script enhances Makefile rather than generate it,
> using configure script can only improve situation (at the cost of extra
> cycles spent detecting)... well, with exception of rare cases bugs in
> configure.ac making it misdetect.

My observations on the list don't quite confirm that "configure" can
only improve the make situation, but I don't use it myself. So, I'll let
those give configure advice who use it.

Michael

Re: [RFC PATCH] Makefile: Turn off the configure target by default

[Ævar Arnfjörð Bjarmason]

On Mon, Oct 11, 2010 at 15:28, Michael J Gruber
<git@drmicha.warpmail.net> wrote:
> Jakub Narebski venit, vidit, dixit 11.10.2010 17:18:
>> Because ./configure script enhances Makefile rather than generate it,
>> using configure script can only improve situation (at the cost of extra
>> cycles spent detecting)... well, with exception of rare cases bugs in
>> configure.ac making it misdetect.
>
> My observations on the list don't quite confirm that "configure" can
> only improve the make situation, but I don't use it myself. So, I'll let
> those give configure advice who use it.

If it doesn't improve it that's a bug that we need to fix. I haven't
seen/found any of the threads/issues in question. Would you mind
pointing some of them out, maybe the problems you cite are easy to
fix.

Re: [RFC PATCH] Makefile: Turn off the configure target by default

[Jonathan Nieder]

Ævar Arnfjörð Bjarmason wrote:
> On Mon, Oct 11, 2010 at 15:28, Michael J Gruber
> <git@drmicha.warpmail.net> wrote:

>> My observations on the list don't quite confirm that "configure" can
>> only improve the make situation, but I don't use it myself. So, I'll let
>> those give configure advice who use it.
>
> If it doesn't improve it that's a bug that we need to fix.

Probably Michael was referring to the FreeBSD 4 thread:
http://thread.gmane.org/gmane.comp.version-control.git/158639

I suspect it has nothing to do with "configure", but given that
most of the active developers do not use autoconf, it tends to be
the first unknown one is tempted to eliminate.

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

[Sverre Rabbelier]

Heya,

On Mon, Oct 11, 2010 at 17:06, Jakub Narebski <jnareb@gmail.com> wrote:
> I like this.

Me too.

> On Mon, 11 Oct 2010, Ævar Arnfjörð Bjarmason wrote:
>>     ERROR: We couldn't run autoconf for you. But you're in luck!
>>     ERROR: Git doesn't actually need autoconf to build.

This is a bit cheeky though. Perhaps just replace that with

>     ERROR: We couldn't run autoconf for you. However, Git doesn't
>     ERROR: actually need autoconf to build.

-- 
Cheers,

Sverre Rabbelier

Re: [RFC PATCH] Makefile: Turn off the configure target by default

[Michael J Gruber]

Jonathan Nieder venit, vidit, dixit 11.10.2010 18:26:
> Ævar Arnfjörð Bjarmason wrote:
>> On Mon, Oct 11, 2010 at 15:28, Michael J Gruber
>> <git@drmicha.warpmail.net> wrote:
> 
>>> My observations on the list don't quite confirm that "configure" can
>>> only improve the make situation, but I don't use it myself. So, I'll let
>>> those give configure advice who use it.
>>
>> If it doesn't improve it that's a bug that we need to fix.
> 
> Probably Michael was referring to the FreeBSD 4 thread:
> http://thread.gmane.org/gmane.comp.version-control.git/158639
> 
> I suspect it has nothing to do with "configure", but given that
> most of the active developers do not use autoconf, it tends to be
> the first unknown one is tempted to eliminate.

That thread was just the hair-trigger, so to say, there were many others
in the past. But it's very typical. We often have "Don't use configure -
it's second class"-type answers to build problems. I don't really
remember that many "I use configure, and it works here"-type answers.

Given the vigorous defense showing up here against deprecating configure
(in the sense of declaring it second class), we can all be confident
that there will be many knowledgeable and helpful answers to build
problems for configure users, right?

Michael

Re: [RFC PATCH] Makefile: Turn off the configure target by default

[Tor Arntsen]

On Tue, Oct 12, 2010 at 10:33, Michael J Gruber
<git@drmicha.warpmail.net> wrote:
[configure etc]
> That thread was just the hair-trigger, so to say, there were many others
> in the past. But it's very typical. We often have "Don't use configure -
> it's second class"-type answers to build problems. I don't really
> remember that many "I use configure, and it works here"-type answers.
>
> Given the vigorous defense showing up here against deprecating configure
> (in the sense of declaring it second class), we can all be confident
> that there will be many knowledgeable and helpful answers to build
> problems for configure users, right?

At the moment './configure; make' works better than just 'make' on
Tru64 and AIX platforms. I have patches somewhere to improve just
'make' on those platforms but I haven't gotten around to post them yet
(need some polishing, or at least re-check against current .git). One
reason I figured it's no hurry is that ./configure actually takes care
of things there for now.

(The series posted by Gary from The Written Word, and mostly included
by now I think, was mainly based on TWW using configure on all
platforms btw. IIRC.)

-Tor