Migrate a bit more logic to pyproject.toml (#9489)

pyproject.toml

@@ -6,7 +6,7 @@ requires = [
     "wheel",
     # Must be kept in sync with `project.dependencies`
     "cffi>=1.12; platform_python_implementation != 'PyPy'",
-    "setuptools-rust>=0.11.4",
+    "setuptools-rust>=1.7.0",
 ]
 build-backend = "setuptools.build_meta"
 
@@ -81,6 +81,13 @@ docstest =  ["pyenchant >=1.6.11", "twine >=1.12.0", "sphinxcontrib-spelling >=4
 sdist = ["build"]
 pep8test = ["black", "ruff", "mypy", "check-sdist"]
 
+[[tool.setuptools-rust.ext-modules]]
+target = "cryptography.hazmat.bindings._rust"
+path = "src/rust/Cargo.toml"
+py-limited-api = true
+rust-version = ">=1.63.0"
+
+
 [tool.black]
 line-length = 79
 target-version = ["py37"]

setup.py

@@ -14,23 +14,6 @@
 
 from setuptools import setup
 
-try:
-    from setuptools_rust import RustExtension
-except ImportError:
-    print(
-        """
-        =============================DEBUG ASSISTANCE==========================
-        If you are seeing an error here please try the following to
-        successfully install cryptography:
-
-        Upgrade to the latest pip and try again. This will fix errors for most
-        users. See: https://pip.pypa.io/en/stable/installing/#upgrading-pip
-        =============================DEBUG ASSISTANCE==========================
-        """
-    )
-    raise
-
-
 # distutils emits this warning if you pass `setup()` an unknown option. This
 # is what happens if you somehow run this file without `cffi` installed:
 # `cffi_modules` is an unknown option.
@@ -47,17 +30,8 @@
     raise RuntimeError("cryptography is not compatible with PyPy3 < 7.3.10")
 
 try:
-    # See pyproject.toml for most of the config metadata.
-    setup(
-        rust_extensions=[
-            RustExtension(
-                "cryptography.hazmat.bindings._rust",
-                "src/rust/Cargo.toml",
-                py_limited_api=True,
-                rust_version=">=1.63.0",
-            )
-        ],
-    )
+    # See pyproject.toml for the config metadata.
+    setup()
 except:
     # Note: This is a bare exception that re-raises so that we don't interfere
     # with anything the installation machinery might want to do. Because we