`unknown cookie value` error when using branchwater RocksDB with manysearch etc.

[ctb]

Running in directory /home/ctbrown/scratch3/sourmash-midgie-raker/splits,

command:

sourmash scripts manysearch 's__Mesorhizobium sp000502715.sig.zip' /group/ctbrowngrp5/sra-metagenomes/20241128-k21-s1000 -k 21 -o /tmp/xxx.csv

Full error:

ksize: 21 / scaled: None / moltype: DNA / threshold: 0.01
searching all sketches in 's__Mesorhizobium sp000502715.sig.zip' against '/group/ctbrowngrp5/sra-metagenomes/20241128-k21-s1000' using 64 threads
selection scaled: None
Loaded DB
Setting scaled=1000 from the database
Reading query(s) from: 's__Mesorhizobium sp000502715.sig.zip'
Loaded 1 query signature(s)
thread '<unnamed>' panicked at /home/conda/feedstock_root/build_artifacts/sourmash_plugin_branchwater_1736968930241/_build_env/.cargo/registry/src/index.crates.io-6f17d22bba15001f/sourmash-0.18.0/src/index/revindex/mod.rs:303:68:
called `Result::unwrap()` on an `Err` value: Custom { kind: Other, error: "unknown cookie value" }
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Traceback (most recent call last):
  File "/home/ctbrown/.conda/envs/grist/bin/sourmash", line 11, in <module>
    sys.exit(main())
             ^^^^^^
  File "/home/ctbrown/.conda/envs/grist/lib/python3.12/site-packages/sourmash/__main__.py", line 20, in main
    retval = mainmethod(args)
             ^^^^^^^^^^^^^^^^
  File "/home/ctbrown/.conda/envs/grist/lib/python3.12/site-packages/sourmash_plugin_branchwater/__init__.py", line 129, in main
    status = sourmash_plugin_branchwater.do_manysearch(
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
pyo3_runtime.PanicException: called `Result::unwrap()` on an `Err` value: Custom { kind: Other, error: "unknown cookie value" }

This happens with at least a couple of hundred different species level queries; I don't think it's the query that's the problem.