[Xastir] Installing on YDL

[Curt, WE7U]

On Wed, 2 Feb 2005, Bruce, KQ4TV wrote:

> RPM ImageMagick-devel-5.5.7.15-1.3 is installed.
> I learned to make sure that was installed a long time ago.

Had to check.  That's the most common problem by far in ImageMagick
not getting found.


> Here is the only part of config.log that mentions ImageMagick.
> About 24 lines down from here is a line that reads "/usr/bin/ld: cannot
> find -lexif" that is the only thing that I can remotely find a
> complaint in the file and I don't know what it is or how to get it?

> -ljpeg -lpng -lexif -ldpstk -ldps
> -lXext -lSM -lICE -lX11 -lbz2 -lxml2 -lz -lpthread -lm  -ldb-4.2 -lXpm
> -lrt -lcurl -lXm -lXt -lXp -lXext
> -lm   -lSM -lICE -lX11  -lshp -lpcre -lproj -ltiff -lgeotiff -lgdal >&5
> /usr/bin/ld: cannot find -lexif


Yep, that looks like your trouble.  "libexif" is what you need.  On
my SuSE system here I have libexif-0.5.12 installed.  Let me explain
a bit, it might help other users to understand:

"configure" will often do a test compile with a particular library
(like ImageMagick) in order to test whether an executable can be
compiled/linked to use it.  We as Xastir developers create
"configure.ac" and "acinclude.m4", which get converted into the
"configure" script by our build tools.  We tell it the name of the
library we wish to check, and tell it one system call (API call)
into the library to try to use.

As configure runs it creates a simple C program that uses that
library call and tries to make a test executable.  If it fails,
configure assumes that the library cannot be used.  That's what's
happening to you.

Now, ImageMagick has a magick-config script that we run in order to
find out what libraries it depends on.  We have to use that script
because ImageMagick can be compiled in a variety of ways, and may
depend on a variety of libraries (very much as Xastir varies in how
it is compiled and what libraries it depends upon).  If the
magick-config script forgets some of these dependencies, or more
likely, if the RPM "spec" file forgets some of them, then you'll end
up with ImageMagick and ImageMagick-devel installed on a system, but
not able to compile any new programs that use it.  The reason is
that you need those additional libraries installed that ImageMagick
is dependent on.  If the spec file had been correct, you wouldn't
have been able to install ImageMagick without having installed the
other libs first, and you wouldn't be in this predicament.

In the past, we've been plagued by ImageMagick libraries that don't
work, RPM packages where the "spec" file doesn't list all of the
dependencies, API changes where it broke our Xastir/ImageMagick
interface in all kinds of strange ways, magick-config scripts that
didn't list all of the dependent libraries, API changes where the
version number reported by IM didn't change (so we couldn't fix our
code to get around it easily).  ImageMagick has been a VERY
problematic library for us.  Configuration/quality control isn't one
of their high points.

W.r.t. your problem, install libexif, then rerun "configure".  You
may have to repeat this a few times until you get all of the
dependent libraries for ImageMagick installed, then you should be
good to go.

--
Curt, WE7U.   APRS Client Comparisons: http://www.eskimo.com/~archer
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