[0.15.18] How to make a ghost science pack

[Murzik]

I made a following simple setup with few labs and 50 red packs in the chests:

lab-setup.jpg (52.53 KiB) Viewed 958 times

Then I ran a research that costs 40 red packs. After it finished I collected all remaining packs from labs and chests.
One would expect to get exactly 10 remaining packs (50 - 40 = 10), but there are 11 (10 full + 1 ghost with 0%):

ghost-pack.jpg (100.51 KiB) Viewed 958 times

I think it's related to a known issue of "lossy science", but still looks fun. There are 2 essential conditions: one of the inserters should be slower than others; and number of packs should be more than required for a particular research.

Steps to reproduce:
1. Load the save:

ghost-pack.zip

(2.59 MiB) Downloaded 91 times

2. Connect labs to power grid (research and packs are already set).
3. Wait for research to finish.
4. Collect all remaining packs.
5. Profit!

[Rseding91]

The pack isn't actually at 0%. It's < 1% and when converted to a % to be shown it ends up showing 0.

It's a side effect of packs being consumed over-time and not something we consider worth putting time into since it works fine you just get little quirks like this.