* [GitHub commits](https://github.com/google/jax/compare/jax-v0.2.26...jax-v0.2.27).
* Breaking changes:
* Support for NumPy 1.18 has been dropped, per the
[deprecation policy](https://jax.readthedocs.io/en/latest/deprecation.html).
Please upgrade to a supported NumPy version.
* The host_callback primitives have been simplified to drop the
special autodiff handling for hcb.id_tap and id_print.
From now on, only the primals are tapped. The old behavior can be
obtained (for a limited time) by setting the ``JAX_HOST_CALLBACK_AD_TRANSFORMS``
environment variable, or the --flax_host_callback_ad_transforms flag.
Additionally, added documentation for how to implement the old behavior
using JAX custom AD APIs ({jax-issue}`8678`).
* Sorting now matches the behavior of NumPy for ``0.0`` and ``NaN`` regardless of the
bit representation. In particular, ``0.0`` and ``-0.0`` are now treated as equivalent,
where previously ``-0.0`` was treated as less than ``0.0``. Additionally all ``NaN``
representations are now treated as equivalent and sorted to the end of the array.
Previously negative ``NaN`` values were sorted to the front of the array, and ``NaN``
values with different internal bit representations were not treated as equivalent, and
were sorted according to those bit patterns ({jax-issue}`9178`).
* {func}`jax.numpy.unique` now treats ``NaN`` values in the same way as `np.unique` in
NumPy versions 1.21 and newer: at most one ``NaN`` value will appear in the uniquified
output ({jax-issue}`9184`).
* Bug fixes:
* host_callback now supports ad_checkpoint.checkpoint ({jax-issue}`8907`).
* New features:
* add `jax.block_until_ready` ({jax-issue}`8941)
* Added a new debugging flag/environment variable `JAX_DUMP_IR_TO=/path`.
If set, JAX dumps the MHLO/HLO IR it generates for each computation to a
file under the given path.
* Added `jax.ensure_compile_time_eval` to the public api ({jax-issue}`7987`).
* jax2tf now supports a flag jax2tf_associative_scan_reductions to change
the lowering for associative reductions, e.g., jnp.cumsum, to behave
like JAX on CPU and GPU (to use an associative scan). See the jax2tf README
for more details ({jax-issue}`9189`).
jaxlib 0.1.75 (Dec 8, 2021)
* New features:
* Support for python 3.10.