Currently :version in dependency versioning refers to the current sub-module's version, which is fine when all submodules are in sync with each other.
In a world where subprojects have differnt versions however this breaks.
It would be really nice that if lein-modules sees a :version it tries to find that project in its source tree and substitutes that version in and then if it cant find it then falls back to the modules version by default.
This should be 100% compatible with what is happening currently, however it would also enable clever version tracking of submodule dependencies which are not all the same.