What happened.

Ouroboros Leios released prototype-2026w38a as a patch to w38. Its notes say schema and wire formats are unchanged, so the update does not require a state wipe or respin. A w38 database is retained, and a stranded w38 node can carry on.

The release also closes two LeiosDb reliability bugs. One had allowed leios.vol.db to grow for the whole sync because endorser blocks remained pinned while copying lagged chain selection. The change pins endorser blocks one batch at a time per copying pass. The other could leave a database wedged after an unclean shutdown following the named UNIQUE-constraint failure; the copy process now repairs that case on its first pass.

Why it matters.

For the prototype track, the in-place patch lowers the operational burden of following the release: an upgrade no longer requires rebuilding state. The two fixes target failures that could make a devnet node unusable on real hardware: volatile-database growth during sync and a database that remains stuck after a crash.

The important boundary is that this is a prototype release on a devnet track. The record does not establish a mainnet change, a hard fork, or a timetable. It also does not provide before-and-after disk-use or sync-time measurements.

What to watch

Watch for fresh-sync measurements of disk behaviour, and for whether the reverted sub-transaction Plutus evaluation returns behind a hard fork.

Sources and limits

Upstream references and independent checks

Digest dated 2026-09-23 · upstream model sonnet. Direct links are matched to all 2 upstream source IDs.

  1. 1
    Prototype 2026w38aDirect upstream source · 7ea80a3de2ba5b13889b744a9c5c75f53d838837
  2. 2
    Release prototype-2026w38aDirect upstream source · 403c2570fd824ee48f57cac5f746bdaee963f1d7
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This Research brief was generated by Terra from a dated upstream research digest. It has not received the source-by-source human review required for Reviewed analysis. Material limit: The evidence is limited to an official prototype-release record; it reports the fixes but gives no measured disk or sync-time results, and the self-repair applies to one named constraint failure rather than general crash safety.