Make MetaPhyscL Available to Applications

[pbauman]

@roystgnr wrote in grinsfem/grins#410

We're also now incompatible with the newest Antioch master, thanks to my mistake - when Antioch is built with MetaPhysicL, it then depends on metaphysicl/compare_types.h, but we don't have any antioch_config function and so there's no way for us to automatically pass on the header directories for that dependency. Not sure what the best fix is.

@pbauman responded with

My knee-jerk reaction is to update the antioch.m4 in libantioch to include the relevant headers if Antioch is using MetaPhyscL. That way, the user shouldn't need to do anything (other than updating their antioch.m4 installation) since MetaPhyscL is header-only.

Further discussions can take place here.

[roystgnr]

In hindsight we should have had an antioch_config from the start; it would also have saved a lot of work when going through the "now we're header-only! whoops, now we're not again!" changes. We'd still need to change antioch.m4 to use antioch_config, but at least it would be one change, and then the application side of configuration would be stable and forwards-compatible.

[pbauman]

In hindsight we should have had an antioch_config from the start

Sorry, I'm not following about antioch_config. Is there an example you could point to?

[roystgnr]

$ $LIBMESH_DIR/bin/libmesh-config 
usage: /h2/roystgnr/LIBRARIES/libmesh-normal/bin/libmesh-config --cppflags --cxxflags --include --libs
       /h2/roystgnr/LIBRARIES/libmesh-normal/bin/libmesh-config --cxx
       /h2/roystgnr/LIBRARIES/libmesh-normal/bin/libmesh-config --cc
       /h2/roystgnr/LIBRARIES/libmesh-normal/bin/libmesh-config --fc
       /h2/roystgnr/LIBRARIES/libmesh-normal/bin/libmesh-config --fflags
       /h2/roystgnr/LIBRARIES/libmesh-normal/bin/libmesh-config --version
       /h2/roystgnr/LIBRARIES/libmesh-normal/bin/libmesh-config --host
       /h2/roystgnr/LIBRARIES/libmesh-normal/bin/libmesh-config --ldflags

See also cppunit-config, cups-config, freetype-config, krb5-config, ...

[pbauman]

Oh, right, of course! Thanks for the reminder.