Geany does a pretty poor job of building the tag files.
The way I managed to get this to work is to:
1. Generate the monolithic package.
2. Perform `fake clean make` on that package.
3. Create a new project that points to the package, such as: `/path/to/fll-0.7.3/build/includes`.
4. Set `file_patterns` to `*.h`.
5. Set `source_patterns` to `*.c`.
6. Set `header_patterns` to `*.h`.
7. Set `ignored_dirs_patterns` to `*;test/*`.
8. Set `ignored_file_patterns` to `*.o;*.obj;*.a;*.lib;*.so;*.dll;*.lo;*.la;*.class;*.jar;*.pyc;*.mo;*.gmo`.
9. Select the `project->generate tags` option.
10. Rename the generate tags file to end in `.c.tags`.
11. Edit that file to replace `_TAG_PROC_CWD` value with something like `/usr/local/fll/includes/` (or `/usr/include/fll` for standard UNIX FHS systems).
The `ignored_file_patterns` has a lot of defaults that geany provided that I probably do not need.
The generated tags file is unusable because geany generates it without the `.c.tags` in the name and geany requires the `.c.tags` in the name to read (which is just plain stupid).