A common problem with compiling wxGTK and Mahogany is, that you need to follow the instructions in Mahogany's README file and use the configure script to set them up as explained. If you use different arguments for configure than those shown in README, things will not work! Also, before running configure again, remove any *.cache and *status files in the working directory or configure will re-use some old settings.
Also, as we are omitting some unused subdirectories from the wxGTK source, to save you download time, you may need to run ``make -k'' rather than just ``make'' to get it to ignore some errors caused by this. On non-Linux/GNU systems, you need to use the GNU linker, i.e. ``gmake'' rather than the default ``make''.