As part of the "2.1 required changes" migration (commit 1b00cb1, 2026-06-25), every recipe in the mod was switched from category = "chemistry-plant" to categories = {"chemistry-plant"} (plural, a list). unpipe.lua was never updated to match. recipe.category is therefore nil for every recipe in the mod, unpipe_lookup[nil] is always nil, and the entire auto-indexing loop has been a complete no-op mod-wide for about 2.5 months.
Suggested fix
In data-updates/unpipe.lua, line 25, change:
local machine = unpipe_lookup[recipe.category]
to read the recipe's categories list (falling back to the old singular field for compatibility):
Suggested Fix
local machine = unpipe_lookup[recipe.categories and recipe.categories[1] or recipe.category]
This restores the intended auto-fluidbox-indexing behavior for every recipe under chemistry-plant, assembling-machine, refinery, micro-assembler, rocket-building, crusher, and centrifuge — not just the two thruster recipes — since the same bug currently silently affects every recipe in those categories that doesn't already have an explicit fluidbox_index hardcoded as a workaround.
I am going to test locally since its a pretty big fix.
