[2.1.14] research_trigger can't be used with multi-level technologies

[frenzied_coder]

I'm the author of the Archipelago mod for Factorio: Space Age (one of 4 different Archipelago randomizer projects for Factorio).

I'm trying to set the `research_trigger` of all the vanilla technologies to `type = "scripted"` to make them impossible to research directly. Instead various external events cause them to be researched as part of the randomizer experience. I still want the technologies to show up in the research GUI to make them discoverable by the player, and I'm adding commentary to the description to give a clue about how to get the mod to grant the technology.

In 2.0, this worked for every vanilla tech, but in 2.1.14 it seems to be rejected for infinite technologies. While I can understand forbidding infinite techs triggered by something like mining a rock, I think `type="scripted"` triggers should still be allowed.

I'm open to the possibility that there's a better way to accomplish what I'm trying to do, but my ideas so far are pretty clunky, like the `unit.ingredients` requiring an impossible to acquire item. I would prefer to show a script trigger with a custom icon and tooltip like i'm doing now, without needing to go through an item prototype to accomplish that.

Here's the specific Lua code that's causing the error: https://github.com/thejoshwolfe/Archipe ... #L174-L179

[Rseding91]

What if you just don’t make a lab that accepts the science packs? Or don’t make it buildable/craftable.

[frenzied_coder]

Yep. I could make that work. It seems pretty clunky though.

What I want is for the technology to be unresearchable. For finite technologies, there's a trigger type specifically for that, `type="scripted"`. For infinite technologies, in order to make them unresearchable, I could configure them to be researchable only via an item that I create that is unobtainable.

That would definitely work, but this seems like a regression from 2.0, doesn't it? If that's my best option, I'll make it work, but I wanted to report this in case it was an oversight.

[Midori_The_Eldretch]

this would help me so much with a copmpat issues im having with PY atm. as it is i have to hope load order manipulation might help