Is the IDE a primary input for building the program? Is the IDE a build dependency? Probably not. Certainly not based on the situation you described.
The LLM equivalent here would be programmatically generating synthetic input or cleaning input for training. You don't need the tools used to generate or clean the data in order to train the model, and thus they can be propriety in the context of an open source model, so long as the source for the model is open (the training data).
Developer's mindset, knowledge and tooling is also a build dependency for any open source code. You can not realistically get the same code without it.
> you can not realistically get the same code without it
You mean the same source code? Because... I agree. That's why it's important for the source to be open. Both in the context of software and language models.
The LLM equivalent here would be programmatically generating synthetic input or cleaning input for training. You don't need the tools used to generate or clean the data in order to train the model, and thus they can be propriety in the context of an open source model, so long as the source for the model is open (the training data).