What's Changed In this major release we are switching our graph computation backend from Aesara to PyTensor, which is a fork of Aesara under PyMC governance. Read the full announcement here: PyMC is Forking Aesara to PyTensor. The switch itself should be rather seamless and you can probably just update your imports: import aesara.tensor as at # old (pymc >=4,< 5) import pytensor.tensor as pt # new (pymc >=5) If you encounter problems updating please check the latest Discussions and don't hesitate to get in toch. Major Changes 🛠 ⚠ Switched the graph backend from Aesara to PyTensor Merged AePPL into pm.logprob submodule Deprecated ordered transform by @ricardoV94 in https://github.com/pymc-devs/pymc/pull/6375 ⚠ The log_likelihood is no longer computed by default but can be added with idata = pm.compute_log_likelihood(idata) or using pm.sample(idata_kwargs=dict(log_likelihood=True)) by @ricardoV94 in https://github.com/pymc-devs/pymc/pull/6374 Refactored Minibatch and stopped using deprecated MRG sampler by @ferrine in https://github.com/pymc-devs/pymc/pull/6304 New Features & Bugfixes 🎉 Added alternative parametrization for AssymetricLaplace by @aloctavodia in https://github.com/pymc-devs/pymc/pull/6337 Allow transforms to work with multiple-valued nodes by @ricardoV94 in https://github.com/pymc-devs/pymc/pull/6341 Support logp derivation in DensityDist by @ricardoV94 in https://github.com/pymc-devs/pymc/pull/6361 Docs & Maintenance 🔧 Removed NoDistribution from docs by @stestoll in https://github.com/pymc-devs/pymc/pull/6316 Bring back logps by @ricardoV94 in https://github.com/pymc-devs/pymc/pull/6272 Add issue templates by @ferrine in https://github.com/pymc-devs/pymc/pull/6327 Fix ordering Transformation for batched dimensions by @TimOliverMaier in https://github.com/pymc-devs/pymc/pull/6255 Fix transforms example by @ricardoV94 in https://github.com/pymc-devs/pymc/pull/6333 Bugfixes to increase robustness against unnamed dims by @michaelosthege in https://github.com/pymc-devs/pymc/pull/6339 Updated GOVERNANCE.md by @canyon289 in https://github.com/pymc-devs/pymc/pull/6358 Fixed overriding user provided mp_ctx strings to pm.sample() on M1 MacOS by @digicosmos86 in https://github.com/pymc-devs/pymc/pull/6363 Simplify measurable transform rewrites by @ricardoV94 in https://github.com/pymc-devs/pymc/pull/6370 Fail docs build on errors in notebooks by @michaelosthege in https://github.com/pymc-devs/pymc/pull/6324 Fix measurable stack and join with interdependent inputs by @ricardoV94 in https://github.com/pymc-devs/pymc/pull/6342 Fix transformed Scan values by @ricardoV94 in https://github.com/pymc-devs/pymc/pull/6343 Curated ecosystem references by @michaelosthege in https://github.com/pymc-devs/pymc/pull/6383 Switched run_mypy.py from pass-listing to fail-listing by @michaelosthege in https://github.com/pymc-devs/pymc/pull/6381 Runing pydocstyle in pre-commit by @michaelosthege in https://github.com/pymc-devs/pymc/pull/6382 New Contributors @digicosmos86 made their first contribution in https://github.com/pymc-devs/pymc/pull/6363 Full Changelog: https://github.com/pymc-devs/pymc/compare/v4.4.0...v5.0.0