How to share modules when using -shared?

[MrSmith via Digitalmars-d-learn]

On Wednesday, 10 December 2014 at 00:44:41 UTC, Justin Whear 
wrote:
> I'm trying to build components that I can dynamically link and 
> keep
> running into an issue with sharing modules between the host and 
> the
> pluggable components. Assuming a layout like this:
>
>   host.d  -- loads components at runtime
>   a.d     -- a module that builds to `a.so`
>   b.d     -- a module that builds to `b.so`
>   common.d
>
> If a.d and b.d both import common.d, all is well.  If host.d 
> imports
> common.d as well, I get this at runtime:
> Fatal Error while loading 'a.so':
> 	The module 'common' is already defined in 'host'.
>
> Test session with sources here: http://pastebin.com/LxsqHhJm
>
> Some of this can be worked around by having host.d use its own 
> extern
> definitions, but how does this work with interfaces?  My tests 
> thus far
> have resulted in object invariant failures.

You can have common in separate .so file, or include it in host.