Chunksmith

Changed

• The 26.3 target moves from 26.3-pre-3 to 26.3-rc-1. This is the whole release. The 26.3 pin is exclusive by construction -- one pack_format per jar -- so on rc-1 the 3.18.1+26.3 jar does not load at all, and "does not load" is the state every 26.3 pre-release leaves the previous build in. pack_format is UNCHANGED at 97 (rc-1's own version.json still reads resource 97.1 / data 121.0, the first 26.3 build in a while not to move it), fabric-api goes to 0.160.3+26.3, and the dependency predicate is 26.3-rc.1.
• No code change was needed. The pre-3 to rc-1 source diff is 14 text files with nothing added, removed or binary-changed, and Chunksmith names none of the six symbols it touches. The one that came closest is ChunkMap: rc-1 widened its chunk-load-failure branch to report and substitute an empty chunk for EVERY non-Error cause, where before only IOException and NbtException took that path. Chunksmith's ChunkMapMixin is accessors plus an @Invoker on tick (visibleChunkMap, toDrop, unloadQueue, pendingUnloads, getMainThreadExecutor), none of which that branch touches.

Notes

• Two rc-1 behaviours change how a pregen run should be READ, not how it runs. SharedConstants.CRASH_EAGERLY flips to false and BlockableEventLoop now rethrows only what isNonRecoverable admits, so an exception thrown from a task on the main loop LOGS under the FATAL marker and the server keeps going. A run that would have crashed on a pre-release comes back green on rc-1: grep the log, do not trust the exit code. Separately, that widened ChunkMap branch means a chunk that fails to load now yields an EMPTY chunk plus a report instead of throwing, so a bad chunk can be COUNTED as generated rather than surfacing. Neither is a Chunksmith change; both are worth knowing before reading a benchmark off this build.
• fabric-api must be 0.160.3+26.3 or newer on rc-1. Earlier builds on the line install and then crash the client: every 26.3 fabric-api declares depends.minecraft = "~26.3-", which cannot tell one prerelease from another, while fabric-renderer-api-v1's LevelExtractorMixin wraps lambda$getViewBlockingState$1 -- a lambda rc-1 deleted when it rewrote getViewBlockingState. Match the Modrinth game_versions label to the exact build. The dedicated server boots clean on the wrong API because that mixin is client-only.