[2.0.21] Construction task for rail ramp never assigned.

[Hares]

Steps to reproduce: unknown found; see below.
Save file: attached.

Context:
I ordered to deconstruct part of the rail system and then rebuild it with some shift.
However, neither personal robots nor network robots never took the task despite items being available.

Problematic ghosts of ramps

122867-problematic-ghost.png (2.37 MiB) Viewed 152 times

Note that all 500 personal robots are inactive; 5 rail ramps are in the inventory.

122867-player-inventory.png (382.63 KiB) Viewed 152 times

Note that all construction robots are inactive in the bot net too.

122867-botnet-stat.png (1.63 MiB) Viewed 152 times

Comment:
Looks like ramps have problems placing when smth is to be deconstructed, the game prohibited for me to place a ramp on Gleba (even with super-force-building) until I removed a crane tree. No video evidence of that remained, will report as a separate issue if occurred again.
Edit: Yep, it does: 122870

[Hares]

Update:
Exact steps to reproduce found.
The problem lies in the game's inability to "hotswap" rail support entity with the one built-in to the rail ramp; removal of elevated rail segments is required but not ordered since they also exist in the new blueprint. Same problem might appear when swapping rail ramp to rail support.

During the recording of the issue, noticed that it does not have 100% reproducibility, only about 40% are positives.

Steps to Reproduce:

1. Import blueprint library attached
2. Deploy "01 - Straight" blueprint, waiting until its construction
3. Deploy "02 - To/From Elevated" blueprint directly over it using super-force building
   • Expected: New blueprint is built
   • Actual: New blueprint may be built or not, its quantum state

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

Copy blueprint

Video evidence attached

[Hares]

Potentially related issue: 122547: [2.0.20] Ghosts don't get revived, even after waiting 20 minutes.