[dependabot]

Bumps lmdb from 2.3.0 to 3.0.0.

Changelog

Sourced from lmdb's changelog.

2026-10-02 3.0.0 ################

Features

• py-lmdb now bundles both LMDB release lines and links them into a single extension module: LMDB 0.9.36 (data format v1) and LMDB 1.0.2 (data format v3). The two formats are mutually unreadable, so each Environment is bound to one engine at construction: an existing database is opened with whatever engine matches its on-disk format, and a new one uses LMDB 0.9 unless told otherwise. Databases written by either version can therefore be opened without the caller doing anything.

• Update the bundled LMDB 0.9 tree from 0.9.35 to 0.9.36 (2026-08-06). It brings ITS#7772 (a sub-page is no longer grown when the data being re-added already fits), ITS#9388 (stat() reported wrong branch_pages/leaf_pages for dupsort databases), ITS#8335 (input validation for MDB_MULTIPLE puts), ITS#10454 (metapage sync on macOS), ITS#8590 (SIGPIPE handling in the compacting copy on macOS) and ITS#10522, which is a visible change of behaviour — see below. It also retires two of py-lmdb's own patches: fix-win-flush-large-write was contributed upstream and landed as ITS#10538, and fix-large-write is reduced to its compacting-copy hunk now that ITS#10054 has fixed mdb_page_flush.

• Update the bundled LMDB 1.0 tree from 1.0.1 to 1.0.2 (2026-09-08). Its only code change is ITS#10575, which fixes committing a write transaction under writemap=True on Windows with the 1.0 engine. The commit failed with "The handle is invalid" unless sync=False or metasync=False was also given (issue #486). Every py-lmdb patch is still needed on 1.0.2; the series was regenerated only for shifted line numbers.

• New lib_version= argument to lmdb.open()/Environment() selects the LMDB version for a new environment (0 for 0.9.x, 1 for 1.0.x). For an existing environment the file's own format wins. New Environment.lib_version() reports the engine backing an environment, and lmdb.version() gained a lib_version= argument to report either bundled version. Setting LMDB_DEFAULT_LIB_VERSION changes the default for new environments process-wide.

• New exception classes for the error codes LMDB 1.0 adds: ProblemError, BadChecksumError, CryptoFailError and EnvEncryptionError. LMDB 1.0's MDB_IS_READONLY maps to the existing ReadonlyError, which 0.9 raises as EACCES, so writing in a read-only transaction raises the same class on both engines.

• New offline verifier for the "verify-then-trust" model: python -m lmdb verify <path>, and the underlying

... (truncated)

Commits

• 4f96e9e Bump version to 3.0.0 for release (#510)
• 22deb82 CFFI: fix cursor use-after-close and close-during-copy races (#509)
• 9079862 Fix concurrency, nested-transaction and parity bugs found in the 3.0 review (...
• dba7b62 Documentation review for 3.0 (#507)
• 63f145d Update the bundled LMDB 1.0 tree to 1.0.2 (#494)
• 79be836 Identify open environments by file, not path (#492)
• 74724ae Fix bugs found by local-model code review (#490)
• 1c749b4 Add offline verifier (verify-then-trust) for both bundled engines (#489)
• cce03fd Validate freeDB record structure in mdb_page_alloc on both engines (#488)
• 0d181ce Update the bundled LMDB 0.9 tree to 0.9.36 (#487)
• Additional commits viewable in compare view