1.0.0-rc1 (2020-05-31)

Hydra 1.0 is a major release introducing many new features and breaking some compatibility.

Features

• Upgrade to OmegaConf 2.0 (Release notes) (#630)
• Optional config type safety via Structured Configs (#629)
• Improve command line and config composition error reporting (#349)
• Hydra config can now be accessed through interpolation using ${hydra:key}, for example ${hydra:job.name} (#325)
• Support for setting environment variable of running job (#7)
• Changes command line processing (requiring + and ~ prefixes for appending and removing items) (#598)
• Introducing @package header for config files (#586)
• Add command line override flags for config_path and config_name (--config-path and --config-name) (#386)
• hydra.main() now take an optional cfg object to passthrough to the function (#575)
• Add hydra.experimental.{initialize_with_file, initialize_with_module} (#574)
• Support for disabling the creation of the .hydra subdirectory by overriding "hydra.output_subdir" to "null" (#324)
• Add hydra.utils.call() to call methods and functions as well as instantiate objects. Search module paths more generically. (#498)
• Add support for overriding package from command line and defaults list (#235)
• Config source is now abstracted, allowing additional config sources to be used (#257)
• New ConfigSource plugin API allowing configs to be provided by external plugins (#367)
• Add isort to ensure imports are always sorted (#340)
• Codebase is now passing mypy --strict type checking (#342)
• Improve performance of plugin discovery and instantiation (#489)
• Modules whose name starts with "_" are skipped during plugin discovery (#494)

Plugins

• Add Ax Sweeper plugin (Shagun Sodhani)
• Add Nevergrad Sweeper plugin (Jérémy Rapin)
• Add Joblib Launcher plugin (Jan-Matthis)
• Add Submitit Launcher plugin to launch jobs to SLURM clusters
• Add Fish shell Tab Completion plugin (Binsheng Liu) (#549)

API Change (Renames, deprecations and removals)

• Drop support Python 2.7 and 3.5 (#313)
• hydra.main() now takes an additional optional config_name and composite-style config_path is deprecated (#395)
• Launcher API launch method now takes an additional initial_job_idx indicating the id of the first job in the batch (#284)
• Singleton metaclass is now exposed at hydra.core.Singleton (#371)
• Moved HydraConfig from hydra.plugins.common.utils to hydra.core (#371)
• Move several formerly internal APIs to hydra/core to ensure plugins does not need to use internal APIs (#371)
• Plugin import now requires explicit name (from hydra.plugins.launcher import Launcher) (#371)
• Object Config "class" field is deprecated in favor of "cls" and will be removed in a future version. (#389)
• Experimental compose API config_file changed to config_name (#395)
• User plugins should be modified to not import twice during plugin discovery. see issue for details. (#482)
• Change hydra.core.plugins.Plugins class to a Singleton. access should be changed to the pattern Plugins.instance().foo() (#489)
• Plugins should now include test fixtures (sweep_runner, task_runner) via a standardized conftest.py (#521)
• Switch Python 3 native namespace packages for plugins (See task for details) (#534)
• Packaged configuration directories now requires an __init__.py at their top level (#536)
• Appending config groups to the defaults list via the command line now requires a + prefix (#598)
• Removing an item from the defaults list by assigning null (db=null) is deprecated, use ~db instead (#598)
• Installed Hydra applications no longer need have an additional entry() function on the stack (#92)

Bug Fixes

• Fix a bug causing sys.exit() error code to not be propagated (#351)
• Shutdown logging subsystem aftter job finishes to ensure log files are flushed and closed (#378)
• Fix a bug with utils.instantiate() failing if params contains interpolated values. (#388)
• Allow hydra.utils.instantiate() to accept non primitive objects for passthrough by name (#400)
• Fix to work when an Hydra app is executed in Jupyter notebook using the %run command (#481)
• Plugins are no longer imported twice during plugin discovery (#482)
• to_absolute_dir(path) now converts relative path to be relative to os.cwd() when used outside of Hydra (#496)

Improved Documentation

• Working examples are provided for all Hydra plugins in plugins/examples (#253)
• The basic tutorial was rewritten to reflect many changes (#602)
• Add a new tutorial covering Structured Configs (#628)