Conda build on OS X

[alicedb2]

I was able to use the conda recipe after prepending the following line in build.sh

export LDFLAGS="-undefined dynamic_lookup -bundle"

Without -undefined dynamic_lookup the linker will complain about missing symbols.

The -bundle is important on Mac lest tt_f90.so and core_f90.so are linked as dylib instead of MachO bundles and dlopen throws a cryptic error about unslidable segment when trying to import tt and so on.