2.5: PoX missed-slot updates

[kantai]

Description

This PR removes the unlock behavior of PoX-4 when solo stackers miss a reward slot. This behavior was broken next: missed reward slot unlocks have consequences for signer set calculation, which has to be addressed. This PR addresses it by removing the unlock behavior.

This PR also adds a test that covers the case of a 2.5 reward cycle having participation but no slots. Such a cycle should still allow the system to make forward progress in 2.5.

[jcnelson]

LGTM as long as CI passes. I notice that this PR doesn't remove the ancillary PoX state that is required for auto-unlock. Is that scheduled for a follow-on PR, or should it be done here?

[kantai]

Is that scheduled for a follow-on PR, or should it be done here?

That's a great question -- it impacts 2.5 activation in testnet, because the PoX contract would necessarily change. I will try to see how easy of a change that is.

[kantai]

LGTM as long as CI passes. I notice that this PR doesn't remove the ancillary PoX state that is required for auto-unlock. Is that scheduled for a follow-on PR, or should it be done here?

Quick follow-up!

The reward set indexes data is used both for the (removed) handle-unlocks method and for stack-increase (its how it figures out which items to increase), so we can't remove that tracking state. However, that tracking state is much less volatile without handle-unlocks (because you never have to perform removals in the stacking-state).

[codecov]

Codecov Report

Attention: Patch coverage is 41.92635% with 205 lines in your changes are missing coverage. Please review.

Project coverage is 77.87%. Comparing base (d2649ff) to head (19a373f).
Report is 22 commits behind head on next.

Additional details and impacted files

@@            Coverage Diff             @@
##             next    #4576      +/-   ##
==========================================
- Coverage   83.25%   77.87%   -5.38%     
==========================================
  Files         456      456              
  Lines      330593   330898     +305     
  Branches      323      317       -6     
==========================================
- Hits       275248   257703   -17545     
- Misses      55337    73187   +17850     
  Partials        8        8              

Files	Coverage Δ
stacks-common/src/types/mod.rs	92.54% <100.00%> (+0.14%)	⬆️
stackslib/src/chainstate/stacks/boot/pox-4.clar	14.33% <ø> (+0.87%)	⬆️
stackslib/src/net/mod.rs	72.93% <100.00%> (+0.01%)	⬆️
stackslib/src/chainstate/stacks/boot/mod.rs	88.25% <89.65%> (-6.50%)	⬇️
...tackslib/src/chainstate/stacks/boot/pox_4_tests.rs	87.57% <36.87%> (-12.10%)	⬇️

... and 171 files with indirect coverage changes

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[obycode]

🎉

[blockstack-devops]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.