Changed the build backend to hatchling. Ones who want to use `setup…

…tools` can change `build-system` section of `pyproject.toml`, the specific config for it was kept.

ci.sh

@@ -66,7 +66,7 @@ fi
 
 python -c "import sys, struct, ssl; print('#' * 70); print('python:', sys.version); print('version_info:', sys.version_info); print('bits:', struct.calcsize('P') * 8); print('openssl:', ssl.OPENSSL_VERSION, ssl.OPENSSL_VERSION_INFO); print('#' * 70)"
 
-python -m pip install -U pip setuptools setuptools_scm wheel build
+python -m pip install -U pip hatchling build
 python -m pip --version
 
 python -m build -nsx .

pyproject.toml

@@ -1,10 +1,11 @@
 [build-system]
-requires = ["setuptools>=61.2"]
-build-backend = "setuptools.build_meta"
+requires = ["hatchling>=1.8.0"]
+build-backend = "hatchling.build"
+#requires = ["setuptools>=61.2", "setuptools_scm[toml]>=3.4.3"]
+#build-backend = "setuptools.build_meta"
 
 [project]
 name = "trio"
-version = "0.22.0"
 authors = [{name = "Nathaniel J. Smith", email = "njs@pobox.com"}]
 license = {text = "MIT OR Apache-2.0"}
 description = "A friendly Python library for async concurrency and I/O"
@@ -45,13 +46,21 @@ dependencies = [
     "cffi>=1.14; os_name == 'nt' and implementation_name != 'pypy'",
     "exceptiongroup >= 1.0.0rc9; python_version < '3.11'",
 ]
+dynamic = ["version"]
+
+[tool.hatch.version]
+path = "trio/_version.py"
 
 [tool.setuptools]
 include-package-data = true
 
 [tool.setuptools.packages]
 find = {namespaces = false}
 
+[tool.setuptools_scm]
+write_to = "trio/_version.py"
+write_to_template = "__version__ = \"{version}\"\n"
+
 [tool.black]
 target-version = ['py37']