Re: configure's dependency on pkg-config

["Jan Djärv" <jan.h.d@swipnet.se>]

Hello.

13 nov 2011 kl. 00:56 skrev Stephen Berman:

> On Sun, 13 Nov 2011 00:12:43 +0100 Jan Djärv <jan.h.d@swipnet.se> wrote:
> 
>> I don't know why you are opposed to installing pkg-config, but it is not Emacs
>> choice.  libxml2 has made pkg-config the way for users of that library to find
>> out compiler and linker flags as well as dependencies on other libraries.  So
>> of course Emacs uses that.  Who are we to argue about the validity of that
>> descision?  Ditto for Gtk, dbus, and others.
> 
> I'm not opposed to installing pkg-config, I just didn't know I was
> supposed to to get Emacs to use libxml2, until I looked in configure.
> If it had been documented in INSTALL, I would have been spared that
> effort and time.  (That libxml2 provides pkg-config data I also didn't
> know: I just checked, and the only mention of "pkg-config" in the entire
> libxml2-2.7.8 source tree is in the ChangeLog, which I didn't read
> before installing libxml2.)
> 

Every package that can be used provides the pkg-config data.  The one for libxml2 is generated from libxml-2.0.pc.in in the source.
I think pkg-config is considered standard, so along with tar, cp and other standard utilities, it is not mentioned.  It is only a problem for people building their own distributions, which is far fewer nowdays that say 10 years ago.  And if you are doing that, pkg-config is really something you need to install.  But adding it to INSTALL is not a big deal.

The reason for not mentioning all the libraries using pkg-config in INSTALL is that almost all new libraries support it.  So we would probably need to add every new library Emacs uses to INSTALL.

	Jan D.