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netcdf-c

DEVOPS
Velocity0.0

Network common data form C library

github.com/Unidata/netcdf-c ↗

netCDF-C has been stuck in release-candidate limbo since 2024

scientific-datazarrcloud-storagec-libraryrelease-candidates
◆Current state
The visible history is almost entirely release candidates. The 4.9.3 line reached a second candidate in December 2024, promising quality-of-life fixes and improved ncZarr support with a quick-start guide for S3 and other cloud object stores, and nothing has appeared since. The 4.9.1 line before it followed the same pattern - two candidates, then a final - and 4.9.0 shipped filter installation improvements and JSON-valued Zarr attributes for GDAL compatibility.
◆Where it's heading
The through-line across every release is Zarr: netCDF is steadily rebuilding itself to store data in cloud object stores rather than files on a filesystem, and successive releases push ncZarr closer to parity. Against that, the release cadence itself is the story here - a candidate that announced a final by end of December 2024 and never produced one.
◆Prediction
Whether 4.9.3 finalises is the open question these entries cannot answer; the stated plan was a documentation-focused candidate followed by a quick final. The Zarr and cloud-storage work is the part most likely to carry into whatever ships next.

◆Recent moves

  1. 1y ago

    Second 4.9.3 candidate improves ncZarr support

    The second 4.9.3 candidate, carrying quality-of-life fixes and improved ncZarr support, with documentation for the .rc file mechanism. The final release it promised for the end of 2024 is not present in this feed.

    View source ↗
  2. 2y ago

    First 4.9.3 candidate opens the ncZarr work

    The first 4.9.3 candidate, opening the same line with szip handling fixes, logging documentation and the bulk of the ncZarr work. Substantively the same release story as the candidate that follows it.

    View source ↗
  3. 3y ago

    4.9.1 adds programmatic access to internal .rc tables

    The 4.9.1 release proper, collecting fixes from 4.9.0 including nc_def_var_fletcher32 and a limited public API for programmatic access to internal .rc tables. Ships with known issues around test race conditions.

    View source ↗
  4. 3y ago

    Second 4.9.1 candidate fixes Conda-Forge packaging

    The second 4.9.1 candidate, whose only manually recorded change is a Conda-Forge packaging fix; the rest is automatically generated cleanup. Carries forward the same known issues as the first candidate.

    View source ↗
  5. 3y ago

    Plugin discovery via nc-config and netcdf_meta.h

    Described as primarily a maintenance candidate, but it adds discoverability for the filter plugin system - a plugins quick-start guide, NC_HAS_BLOSC and NC_HAS_BZ2 metadata entries, and new nc-config query options.

    View source ↗
  6. 4y ago

    JSON-valued Zarr attributes for GDAL interoperability

    Simplifies filter installation by dropping an extra shell script and allows reading and writing JSON-valued Zarr attributes, the domain-specific metadata GDAL relies on. An early step in making netCDF's Zarr support interoperable rather than self-contained.

    View source ↗