Bug#582860: [libgtk2.0-dev] pkg-config requires too many libraries

[Peter Fritzsche]

Package: libgtk2.0-dev
Version: 2.20.1-1
Severity: normal

I tried to package some software which uses gtk+ and dpkg-shlibdeps just 
hammers my output with messages like 

dependency on xxxx could be avoided if ....


I checked your /usr/lib/pkgconfig/gtk+-2.0.pc and noticed that there is a 
Require statement with many other pkg-config files. /usr/lib/libgtk-
x11-2.0.so.0.2000.1 doesn't seem have have so have unresolved symbols. So 
either the header files generate code which creates otherwise unresolved 
symbols or you don't use Require in /usr/lib/pkgconfig/gtk+-2.0.pc correctly. 
Please see the difference with Require.private in gtk+-2.0.pc:

$ pkg-config --libs gtk+-2.0
-lgtk-x11-2.0
$ pkg-config --cflags gtk+-2.0
-pthread -I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include -
I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pango-1.0 -
I/usr/include/gio-unix-2.0/ -I/usr/include/pixman-1 -I/usr/include/freetype2 -
I/usr/include/libpng12 -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include  

$ pkg-config --libs --static gtk+-2.0
-pthread -lgtk-x11-2.0 -lgdk-x11-2.0 -latk-1.0 -lpangoft2-1.0 -lXinerama -lXi 
-lXrandr -lXcursor -lXcomposite -lXdamage -lgdk_pixbuf-2.0 -ltiff -ljpeg -
ljasper -lpangocairo-1.0 -lXext -lXfixes -lcairo -lgio-2.0 -lresolv -lpixman-1 
-lpng12 -lm -lxcb-render-util -lXrender -lxcb-render -lX11 -lpthread -lxcb -
lXau -lXdmcp -lpango-1.0 -lfontconfig -lexpat -lfreetype -lz -lgobject-2.0 -
lgmodule-2.0 -ldl -lgthread-2.0 -lrt -lglib-2.0  
$ pkg-config --cflags --static gtk+-2.0
-pthread -I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include -
I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pango-1.0 -
I/usr/include/gio-unix-2.0/ -I/usr/include/pixman-1 -I/usr/include/freetype2 -
I/usr/include/libpng12 -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include

And now how it looks today with Require:
$ pkg-config --libs gtk+-2.0       
-pthread -lgtk-x11-2.0 -lgdk-x11-2.0 -latk-1.0 -lpangoft2-1.0 -lgdk_pixbuf-2.0 
-lm -lpangocairo-1.0 -lcairo -lgio-2.0 -lpango-1.0 -lfreetype -lfontconfig -
lgobject-2.0 -lgmodule-2.0 -lgthread-2.0 -lrt -lglib-2.0
$ pkg-config --cflags gtk+-2.0         
-pthread -I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include -
I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pango-1.0 -
I/usr/include/gio-unix-2.0/ -I/usr/include/pixman-1 -I/usr/include/freetype2 -
I/usr/include/libpng12 -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include

$ pkg-config --libs --static gtk+-2.0
-pthread -lgtk-x11-2.0 -lgdk-x11-2.0 -latk-1.0 -lpangoft2-1.0 -lXinerama -lXi 
-lXrandr -lXcursor -lXcomposite -lXdamage -lgdk_pixbuf-2.0 -ltiff -ljpeg -
ljasper -lpangocairo-1.0 -lXext -lXfixes -lcairo -lgio-2.0 -lresolv -lpixman-1 
-lpng12 -lm -lxcb-render-util -lXrender -lxcb-render -lX11 -lpthread -lxcb -
lXau -lXdmcp -lpango-1.0 -lfontconfig -lexpat -lfreetype -lz -lgobject-2.0 -
lgmodule-2.0 -ldl -lgthread-2.0 -lrt -lglib-2.0
$ pkg-config --cflags --static gtk+-2.0
-pthread -I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include -
I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pango-1.0 -
I/usr/include/gio-unix-2.0/ -I/usr/include/pixman-1 -I/usr/include/freetype2 -
I/usr/include/libpng12 -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include

So the cflags are untouched, but the libs are a lot cleaner for non static 
compilations. Please change it to Require.private or give a good reason not to 
do so (broken build systems of other applications are no good reason). It 
should cleanup many dependencies in our repository which aren't needed at all 
and only happens due to gtk+-2.0's bad pkg-config file.

--- System information. ---
Architecture: amd64
Kernel:       Linux 2.6.32-5-amd64

Debian Release: squeeze/sid
  500 unstable        ftp.uni-kl.de 
  500 unstable        ftp.debian.org 
    1 experimental    ftp.debian.org 

--- Package information. ---
Depends                      (Version) | Installed
======================================-+-=================
libgtk2.0-0               (= 2.20.1-1) | 2.20.1-1
libgtk2.0-common                       | 2.20.1-1
libc6                       (>= 2.2.5) | 2.10.2-9
libglib2.0-0               (>= 2.23.6) | 2.24.1-1
libglib2.0-dev             (>= 2.23.6) | 2.24.1-1
libpango1.0-dev              (>= 1.20) | 1.28.0-1
libatk1.0-dev              (>= 1.29.2) | 1.30.0-1
libcairo2-dev           (>= 1.6.4-6.1) | 1.8.10-4
libx11-dev              (>= 2:1.0.0-6) | 2:1.3.3-3
libxext-dev             (>= 1:1.0.1-2) | 2:1.1.1-3
libxinerama-dev       (>= 1:1.0.1-4.1) | 2:1.1-3
libxi-dev               (>= 1:1.0.1-4) | 2:1.3-4
libxrandr-dev            (>= 1:1.2.99) | 2:1.3.0-3
libxcursor-dev                         | 1:1.1.10-2
libxfixes-dev           (>= 1:3.0.0-3) | 1:4.0.4-2
libxcomposite-dev       (>= 1:0.2.0-3) | 1:0.4.1-1
libxdamage-dev          (>= 1:1.0.1-3) | 1:1.1.2-1
pkg-config                             | 0.24-1
libxml2-utils                          | 2.7.7.dfsg-2


Recommends      (Version) | Installed
=========================-+-===========
python           (>= 2.4) | 2.5.4-9
debhelper                 | 7.4.20


Suggests           (Version) | Installed
============================-+-===========
libgtk2.0-doc                |