Yeah, might be lucky but I think that if any of the symbol checksums have changed (likely between 3.14 and 3.18) the module probably won't load.
Don't know if OpenWrt uses any extra module validation options in the kernel config but mostly that isn't done.To resolve these problems there probably needs to be a packages directory along with builds for manual download and install.
A pain but at this stage probably needed.Ian
If these were some semi-long maintained fork (like McWRT AA) then I agree that a dedicated package directory could be provided.
However, given that these are fairly ephemeral test builds of trunk snapshots I'm not sure if those producing them would be keen on regenerating all the packages every release (which seems to be about every couple of weeks).
Ultimately, given that trunk now uses 3.18 by default (and CC will too), I guess the main question is why the trunk packages haven't (yet) all been rebuilt for 3.18.