What did you do?
I connected chemical plants in a daisy-chain fashion via red wires, with each having "Set Recipe" enabled and a recipe being supplied along that wire.
What happened?
Chemical plants after the first in the daisy chain did not set their recipe.
What did you expect to happen instead?
I would expect chemical plants to set their recipe regardless of whether they were the first in the chain or later in it.
Does it happen always, once, or sometimes?
If I delete only the chemical plants and undo, it happens. If I delete them AND the inserters, it doesn't. I think what is occurring is that the secondary-daisy-chain plants are refusing to set their recipe because they have already received an ingredient for the recipe via the waiting inserters??
Video of weird behavior in action:
Minor Notes:
Behavior was originally observed on a modded game. I then loaded it up unmodded (only Space Age and Rails) to check if behavior persisted. Video was recorded after loading unmodded.
Addendum:
The location/chain direction of the chemical plants appears to make a difference on whether the behavior occurs.
[2.0.42] Chemical plant does not Set Recipe from signal when daisy chained and already supplied with ingredient.
Re: [2.0.42] Chemical plant does not Set Recipe from signal when daisy chained and already supplied with ingredient.
Thanks for the report. This is not a bug. Inserters managed to put some trash while recipe was not yet set and it needs to be taken out of trash inventory before a new recipe will be set.
Re: [2.0.42] Chemical plant does not Set Recipe from signal when daisy chained and already supplied with ingredient.
I'll take your word for it that it's not a bug, but the behavior certainly seems strange to me. It's inconsistent between the shown chemical plants, where the only difference between them is location along a series of red wires.