Make deprecation warning more visible and mention --use-pep517

Author: abravalheri

pytest.ini

@@ -40,7 +40,7 @@ filterwarnings=
 	ignore:The Windows bytes API has been deprecated:DeprecationWarning
 
 	# https://github.com/pypa/setuptools/issues/2823
-	ignore:setuptools.installer is deprecated.
+	ignore:(.|\s)*setuptools.installer. is deprecated(.|\s)*
 
 	# https://github.com/pypa/setuptools/issues/917
 	ignore:setup.py install is deprecated.

setuptools/installer.py

@@ -24,11 +24,7 @@ def fetch_build_egg(dist, req):  # noqa: C901  # is too complex (16)  # FIXME
     """Fetch an egg needed for building.
 
     Use pip/wheel to fetch/build a wheel."""
-    warnings.warn(
-        "setuptools.installer is deprecated. Requirements should "
-        "be satisfied by a PEP 517 installer.",
-        SetuptoolsDeprecationWarning,
-    )
+    _DeprecatedWorkflow.warn(req, stacklevel=2)
     # Warn if wheel is not available
     try:
         pkg_resources.get_distribution('wheel')
@@ -102,3 +98,22 @@ def strip_marker(req):
     req = pkg_resources.Requirement.parse(str(req))
     req.marker = None
     return req
+
+
+class _DeprecatedWorkflow(SetuptoolsDeprecationWarning):
+    """Deprecated installation or configuration method for requirement: {req}
+    !!\n\n
+    ########################
+    # Deprecated Workflow #
+    ########################
+    `setuptools.installer` is deprecated. Requirements should
+    be satisfied by a PEP 517 installer.
+
+    If you are using `pip install` you can try adding the `--use-pep517` flag.
+    \n\n!!
+    """
+
+    @classmethod
+    def warn(cls, req, stacklevel=1):
+        msg = cls.__doc__.format(req=req)
+        warnings.warn(msg, cls, stacklevel=stacklevel+1)