# JAX v0.3.17 — JAX release v0.3.17

- Product: JAX (https://whatsnew.fyi/product/jax)
- Vendor: Google
- Date: 2022-08-31
- Version: v0.3.17
- Original notes: https://github.com/jax-ml/jax/releases/tag/jax-v0.3.17
- Permalink: https://whatsnew.fyi/product/jax/releases/v0.3.17

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Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **fixed** — Fix corner case issue in gradient of lax.pow with an exponent of zero
- **removed** — Remove jax.checkpoint concrete option following previous deprecation
- **added** — Add jax.pure_callback that enables calling back to pure Python functions from compiled functions
- **removed** — Remove deprecated DeviceArray.tile() method
- **deprecated** — Deprecate DeviceArray.to_py() in favor of np.asarray(x)

* [GitHub commits](https://github.com/google/jax/compare/jax-v0.3.16...jax-v0.3.17).
* Bugs
  * Fix corner case issue in gradient of `lax.pow` with an exponent of zero (#12041)
* Breaking changes
  * `jax.checkpoint`, also known as `jax.remat`, no longer supports the `concrete` option, following the previous version's deprecation; see [JEP 11830](https://jax.readthedocs.io/en/latest/jep/11830-new-remat-checkpoint.html).
* Changes
  * Added `jax.pure_callback` that enables calling back to pure Python functions from compiled functions (e.g. functions decorated with `jax.jit` or `jax.pmap`).
* Deprecations:
  * The deprecated `DeviceArray.tile()` method has been removed. Use `jax.numpy.tile` (#11944).
  * `DeviceArray.to_py()` has been deprecated. Use `np.asarray(x)` instead.