Unstable backend test failure

[jsdw]

There appears to be a new unstable backend test failure:

https://github.com/paritytech/subxt/actions/runs/7089806307/job/19295367538

I wonder whether this is the result of #1305, or otherwise just another intermittent issue not addressed properly by that.

[lexnv]

The test seem to timeout after a very long time, which may happen if:

• tx finalized hash is older than whatever chainHead has reported
• chainHead or backend produces a Finalized event; then a NewBlock event for the same hash (out of order)
• we somehow clear the seen hashes incorrectly, which loses track of the finalized block
  

  subxt/subxt/src/backend/unstable/mod.rs

  Line 469 in cc5c78a

  let mut seen_blocks = HashMap::new();

[jsdw]

Yeahh, lemme look into it a bit; I do feel like it's likely to have been introduced by that recent fix!

[lexnv]

Other failures possibly related to this:

• https://github.com/paritytech/subxt/actions/runs/7165550289/job/19507726478
• https://github.com/paritytech/subxt/actions/runs/7166080771/job/19509347216

[jsdw]

I think we addressed this now so I'll close and we can re-open if more issues :)