backfill_sidecars.py skipped the .h5 write when a file produced no
samples, with the stated intent of not replacing it with an empty
placeholder. That silently preserved output from a superseded decoder.
After the record-chain fix, 415 histogram files stopped decoding (216 on
BE18193, 199 on BE9440) but kept .h5 files whose peaks ran up to 400x
the device-reported PPV. Those were feeding charts and the
false-trigger detector with nothing marking them. The .h5 is now
removed in that case and the run reports stale_h5_removed.
Store-wide effect, series-3, decoded peak vs device-reported PPV:
waveform 1307/1307 (100%), mean abs ratio error 0.00000
histogram 4434/4435 (100%)
Both were 99% with a tail of 18 and 25 wrong files respectively.
The 415 files are a genuine unmapped format variant, not a regression:
their bodies open `00 00 00 01 0a 00` (valid block header, marker 0a at
[4], block_ctr 256) but block[28:32] matches neither known tail, and no
stride from 8 to 64 bytes places a marker at [4] consistently. Bodies
are very large (one is 360,573 bytes). They were previously being
decoded by the WAVEFORM codec, which accepted them and returned garbage
- so the gap pre-dates today's work; the fix only exposed it. Logged as
an open question in the protocol reference.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HgTe8CamXAHcAmaQ6QNcog