Re: present but cannot be compiled (Was: configure: WARNING: ## Report this to address@hidden ##)

[Akim Demaille]

Thanks for the bug report!

Unfortunately, the problem comes from the package itself, not from
Autoconf.  The configure.ac script needs to be updated.  Please, send
all this message (which your output attached) to the bug list (or the
authors) of the package you were trying to configure.

Below two parts of the Autoconf documentation are included: 1. the
documentation of AC_CHECK_HEADER(S), and 2. what's to be done to
upgrade configure.ac.

Thanks!

----------------------------------------------------------------------

Generic Header Checks
---------------------

   These macros are used to find system header files not covered by the
"particular" test macros.  If you need to check the contents of a header
as well as find out whether it is present, you have to write your own
test for it (*note Writing Tests::).

 - Macro: AC_CHECK_HEADER (HEADER-FILE, [ACTION-IF-FOUND],
          [ACTION-IF-NOT-FOUND], [INCLUDES = `default-includes'])
     If the system header file HEADER-FILE is compilable, execute shell
     commands ACTION-IF-FOUND, otherwise execute ACTION-IF-NOT-FOUND.
     If you just want to define a symbol if the header file is
     available, consider using `AC_CHECK_HEADERS' instead.

     For compatibility issues with older versions of Autoconf, please
     read below.

 - Macro: AC_CHECK_HEADERS (HEADER-FILE..., [ACTION-IF-FOUND],
          [ACTION-IF-NOT-FOUND], [INCLUDES = `default-includes'])
     For each given system header file HEADER-FILE in the
     whitespace-separated argument list that exists, define
     `HAVE_HEADER-FILE' (in all capitals).  If ACTION-IF-FOUND is
     given, it is additional shell code to execute when one of the
     header files is found.  You can give it a value of `break' to
     break out of the loop on the first match.  If ACTION-IF-NOT-FOUND
     is given, it is executed when one of the header files is not found.

     For compatibility issues with older versions of Autoconf, please
     read below.

   Previous versions of Autoconf merely checked whether the header was
accepted by the preprocessor.  This was changed because the old test was
inappropriate for typical uses.  Headers are typically used to compile,
not merely to preprocess, and the old behavior sometimes accepted
headers that clashed at compile-time.  If you need to check whether a
header is preprocessable, you can use `AC_PREPROC_IFELSE' (*note
Running the Preprocessor::).

   This scheme, which improves the robustness of the test, also requires
that you make sure that headers that must be included before the
HEADER-FILE be part of the INCLUDES, (*note Default Includes::).  If
looking for `bar.h', which requires that `foo.h' be included before if
it exists, we suggest the following scheme:


AC_CHECK_HEADERS([foo.h])
AC_CHECK_HEADERS([bar.h], [], [],
[#if HAVE_FOO_H
# include <foo.h>
# endif
])

----------------------------------------------------------------------

Header Present But Cannot Be Compiled
=====================================

   The most important guideline to bear in mind when checking for
features is to mimic as much as possible the intended use.
Unfortunately, old versions of `AC_CHECK_HEADER' and `AC_CHECK_HEADERS'
failed to follow this idea, and called the preprocessor, instead of the
compiler, to check for headers.  As a result, incompatibilities between
headers went unnoticed during configuration, and maintainers finally
had to deal with this issue elsewhere.

   As of Autoconf 2.56 both checks are performed, and `configure'
complains loudly if the compiler and the preprocessor do not agree.
For the time being the result used is that of the preprocessor, to give
maintainers time to adjust their `configure.ac', but in the near
future, only the compiler will be considered.

   Consider the following example:

     $ cat number.h
     typedef int number;
     $ cat pi.h
     const number pi = 3;
     $ cat configure.ac
     AC_INIT
     AC_CHECK_HEADERS(pi.h)
     $ autoconf -Wall
     $ ./configure
     checking for gcc... gcc
     checking for C compiler default output... a.out
     checking whether the C compiler works... yes
     checking whether we are cross compiling... no
     checking for suffix of executables...
     checking for suffix of object files... o
     checking whether we are using the GNU C compiler... yes
     checking whether gcc accepts -g... yes
     checking for gcc option to accept ANSI C... none needed
     checking how to run the C preprocessor... gcc -E
     checking for egrep... grep -E
     checking for ANSI C header files... yes
     checking for sys/types.h... yes
     checking for sys/stat.h... yes
     checking for stdlib.h... yes
     checking for string.h... yes
     checking for memory.h... yes
     checking for strings.h... yes
     checking for inttypes.h... yes
     checking for stdint.h... yes
     checking for unistd.h... yes
     checking pi.h usability... no
     checking pi.h presence... yes
     configure: WARNING: pi.h: present but cannot be compiled
     configure: WARNING: pi.h: check for missing prerequisite headers?
     configure: WARNING: pi.h: proceeding with the preprocessor's result
     configure: WARNING:     ## ------------------------------------ ##
     configure: WARNING:     ## Report this to address@hidden ##
     configure: WARNING:     ## ------------------------------------ ##
     checking for pi.h... yes

The proper way the handle this case is using the fourth argument (*note
Generic Headers::):

     $ cat configure.ac
     AC_INIT
     AC_CHECK_HEADERS(number.h pi.h,,,
     [[#if HAVE_NUMBER_H
     # include <number.h>
     #endif
     ]])
     $ autoconf -Wall
     $ ./configure
     checking for gcc... gcc
     checking for C compiler default output... a.out
     checking whether the C compiler works... yes
     checking whether we are cross compiling... no
     checking for suffix of executables...
     checking for suffix of object files... o
     checking whether we are using the GNU C compiler... yes
     checking whether gcc accepts -g... yes
     checking for gcc option to accept ANSI C... none needed
     checking for number.h... yes
     checking for pi.h... yes

----------------------------------------------------------------------

Hello,

I don't have more time now for look this... so, I mail here, how it says..



address@hidden:/usr/local/nomad/gnomedap-0.5.1# ./configure 
--prefix=/usr/local/nomad --exec-prefix=/usr/local/nomad --
with-njb-prefix=/usr/local/nomad
checking for a BSD-compatible install... /usr/bin/ginstall -c
checking whether build environment is sane... yes
checking whether make sets $(MAKE)... yes
checking for working aclocal-1.4... missing
checking for working autoconf... found
checking for working automake-1.4... missing
checking for working autoheader... found
checking for working makeinfo... found
checking build system type... i686-pc-linux-gnu
checking host system type... i686-pc-linux-gnu
checking for gcc... gcc
checking for C compiler default output... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables...
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ANSI C... none needed
checking for ld used by GCC... /usr/i386-slackware-linux/bin/ld
checking if the linker (/usr/i386-slackware-linux/bin/ld) is GNU ld... yes
checking for /usr/i386-slackware-linux/bin/ld option to reload object files... 
-r
checking for BSD-compatible nm... /usr/bin/nm -B
checking for a sed that does not truncate output... /usr/bin/sed
checking whether ln -s works... yes
checking how to recognise dependent libraries... pass_all
checking command to parse /usr/bin/nm -B output... ok
checking how to run the C preprocessor... gcc -E
checking for egrep... grep -E
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking dlfcn.h usability... yes
checking dlfcn.h presence... yes
checking for dlfcn.h... yes
checking for ranlib... ranlib
checking for strip... strip
checking for objdir... .libs
checking for gcc option to produce PIC... -fPIC
checking if gcc PIC flag -fPIC works... yes
checking if gcc static flag -static works... yes
checking if gcc supports -c -o file.o... yes
checking if gcc supports -c -o file.lo... yes
checking if gcc supports -fno-rtti -fno-exceptions... yes
checking whether the linker (/usr/i386-slackware-linux/bin/ld) supports shared 
libraries... yes
checking how to hardcode library paths into programs... immediate
checking whether stripping libraries is possible... yes
checking dynamic linker characteristics... GNU/Linux ld.so
checking if libtool supports shared libraries... yes
checking whether to build shared libraries... yes
checking whether to build static libraries... no
checking whether -lc should be explicitly linked in... no
creating libtool
checking for strerror in -lcposix... no
checking for gcc... (cached) gcc
checking whether we are using the GNU C compiler... (cached) yes
checking whether gcc accepts -g... (cached) yes
checking for gcc option to accept ANSI C... (cached) none needed
checking for ANSI C header files... (cached) yes
checking for gconftool-2... /usr/bin/gconftool-2
checking for intltool >= 0.18... 0.25 found
checking for perl... /usr/bin/perl
checking for pkg-config... /usr/bin/pkg-config
checking for GLIB - version >= 2.0.0... yes (version 2.2.1)
checking for libgnome-2.0 >= 1.102.0                             libgnomeui-2.0 
>= 2.1.90                         
libbonoboui-2.0 >= 1.97.0                                libbonobo-2.0 >= 
1.101.2                                
gthread-2.0 >= 1.3.7                                      gtk+-2.0 >= 2.0.7     
                                  
libxml-2.0 >= 2.4.3                                       libglade-2.0 >= 
1.99.2                                  gconf-
2.0 >= 1.1.1                                        gnome-vfs-2.0 >= 1.1        
                            gdk-pixbuf-
2.0 >= 1.3.7... yes
checking GNOME_CFLAGS... -DORBIT2=1 -pthread -I/usr/include/libgnome-2.0 
-I/usr/include/glib-2.0 -I/usr/lib/glib-
2.0/include -I/usr/include/orbit-2.0 -I/usr/include/libbonobo-2.0 
-I/usr/include/gconf/2 -I/usr/include/gnome-vfs-2.0 -
I/usr/lib/gnome-vfs-2.0/include -I/usr/include/linc-1.0 
-I/usr/include/bonobo-activation-2.0 -I/usr/include/libgnomeui-
2.0 -I/usr/include/libgnomecanvas-2.0 -I/usr/include/gtk-2.0 
-I/usr/include/libart-2.0 -I/usr/include/libbonoboui-2.0 -
I/usr/include/pango-1.0 -I/usr/X11R6/include -I/usr/include/freetype2 
-I/usr/lib/gtk-2.0/include -I/usr/include/atk-
1.0 -I/usr/include/libxml2 -I/usr/include/libglade-2.0
checking GNOME_LIBS... -pthread -Wl,--export-dynamic -L/usr/X11R6/lib 
-lgnomeui-2 -lSM -lICE -lbonoboui-2 -lgnomecanvas-
2 -lgnome-2 -lart_lgpl_2 -lpangoft2-1.0 -lbonobo-2 -lglade-2.0 -lgtk-x11-2.0 
-lxml2 -lz -lgdk-x11-2.0 -latk-1.0 -
lpangoxft-1.0 -lpangox-1.0 -lpango-1.0 -lgconf-2 -lgnomevfs-2 
-lbonobo-activation -lORBit-2 -llinc -lgthread-2.0 -
lgdk_pixbuf-2.0 -lm -lgobject-2.0 -lgmodule-2.0 -ldl -lglib-2.0
Using config source xml::/etc/gconf/gconf.xml.defaults for schema installation
Using $(sysconfdir)/gconf/schemas/ as install directory for schema files
checking locale.h usability... yes
checking locale.h presence... yes
checking for locale.h... yes
checking for LC_MESSAGES... yes
checking libintl.h usability... yes
checking libintl.h presence... yes
checking for libintl.h... yes
checking for dgettext in libc... yes
checking for bind_textdomain_codeset... yes
checking for msgfmt... /usr/bin/msgfmt
checking for dcgettext... yes
checking for gmsgfmt... /usr/bin/msgfmt
checking for xgettext... /usr/bin/xgettext
checking for scrollkeeper-config... /usr/bin/scrollkeeper-config
checking libnjb.h usability... yes
checking libnjb.h presence... no
configure: WARNING: libnjb.h: accepted by the compiler, rejected by the 
preprocessor!
configure: WARNING: libnjb.h: proceeding with the preprocessor's result
configure: WARNING:     ## ------------------------------------ ##
configure: WARNING:     ## Report this to address@hidden ##
configure: WARNING:     ## ------------------------------------ ##
checking for libnjb.h... no
configure: error: *** libnjb.h C header is needed (missing -dev package?) ***