Breaking Changes
fastcore v2 removes or relocates a number of APIs that now have better alternatives. If you use from fastcore.utils import * (or fastcore.all), most of these changes won't affect you.
The breaking changes: Param is gone from fastcore.script; use plain type annotations with docments, or typing.Annotated[type, "help"], optionally with a dict of argparse arguments for advanced features. L's starmap, starfilter, and the other star*/rstar* methods are replaced by the star and rstar function adapters, which compose with every L method (e.g. t.map(star(f))); relatedly, spread is replaced by star, and dspread is renamed to dstar. Async helpers now live in the new fastcore.aio module: run_sync, iter_sync, and ctx_sync moved there from net, and maybe_await, then, mapa, acache, reawaitable, is_async_callable, and the other async utilities moved there from xtras. Config and the config file functions moved from foundation to xtras. fastcore.net lost its request builders (urlrequest, urlsend, do_request, urlcheck) and clean_type_str is gone. parallel_gen moved to fastai. Python 3.11 or later is now required.
If you need the old APIs, pin fastcore<2.