libapr0-dev: headers not found
This bug should probably be closed, as it seems to be a product of
user confusion about what apxs -q INCLUDEDIR does. That option has
historically (and always will, I suspect) output a single directory,
showing the location of the apache header files, containing the
prototypes for the ap_* functions.
The fact that ap_* functions also reference apr_* and apu_* functions,
and thus will need apr's headers present is irrelevant, much in the
way that ap_* functions referencing openssl headers, or db4.2 headers
shouldn't be something apxs -q INCLUDEDIR cares about.
If you want a full list of -I/foo include directives to feed gcc which
should fulfil apache's full list of required include search paths, you
want "apxs2 -q EXTRA_INCLUDES".
If you find that "apxs2 -q EXTRA_INCLUDES" is also incomplete, please
let us know and we'll fix it up to DTRT, but as far as I currently know,
it should work.