Hatchling wheel build fails if project name doesn't match package dir; fix via tool.hatch.build.targets.wheel.packages

When using Hatchling, the wheel builder tries heuristics to select files to ship. If your distribution name (e.g. craic-demo) implies a normalized module name (e.g. craic_demo) but your repo doesn't contain a matching package directory, editable builds can fail with: ValueError: Unable to determine which files to ship... The most likely cause is that there is no directory that matches the name of your project. This can surface via uv run because it builds the project by default. Verified 2026-03 while running uv run --with pytest pytest on a Hatchling project where the only importable package directory was src/.

Add an explicit file selection config for Hatchling, e.g. [tool.hatch.build.targets.wheel] packages = ["<your-package-dir>"] (for a src-layout package: packages = ["src/<pkg>"], or for a top-level package dir: packages = ["<pkg>"]). If you want CI commands like uv run pytest to work without building the project, you can alternatively use uv run --no-project ....