[Gimp-print-devel] PKG_LIB_DIR/PKGMODULEDIR expansion issues

[Matsumura, G. <gm9...@oh...>]

Greetings,

My build of Gutenprint, built through Void Linux's standardized build
process, was unable to find the module directories due to PKGMODULEDIR
being defined in config.h as:
#define PKGMODULEDIR "${exec_prefix}/lib64/gutenprint/5.3/modules"

Since the C processor cannot expand exec_prefix, it remains in the path
at runtime and cannot be resolved.

Attached is the config.summary from the build. In particular, the
following flag passed to configure seemed to be responsible:
--libdir=\${exec_prefix}/lib64

There seems to be a specific case in configure.ac for when libdir is
defined as \${exec_prefix}/lib, but this would not cover my case.

This seems to be similar to the problem described here:
https://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoconf-2.71/html_node/Defining-Directories.html

Is there a recommended way to patch configure.ac so that such an option
works correctly? The above reference suggests either moving definitions
to compile-time options in Makefile.am, which, looking at the repository
history, seems to have been done in gutenprint in the past, or using an
additional macro to resolve the pathname.

Thank you for reading this and in advance for any reply.

Regards,
    George