Ah, I guess it's supposed to use rocket turrets in its recipe, not rocket launchers (even though the vanilla version of the spidertron rocket weapon seems to be based on individual rocket launchers, not the rocket turret). The required weapon technologies are updated based on the selected weapons, and for rockets, it is changed from rocket turret to rocket launcher, since that's the part used for the recipe.
There is a startup setting to disable these changes, which might be the correct solution here, but I do think this could use some improvement (since it cuts out not only gleba, but also carbon fiber from the requirements).
