Merge pull request #431 from takluyver/deprecate-default-setup-py

Prepare for not generating setup.py by default

flit/__init__.py

@@ -79,7 +79,14 @@ def main(argv=None):
         help="Select a format to build. Options: 'wheel', 'sdist'"
     )
 
-    parser_build.add_argument('--no-setup-py', action='store_false', dest='setup_py',
+    parser_build.add_argument('--setup-py', action='store_true',
+        help=("Generate a setup.py file in the sdist. "
+              "The sdist will work with older tools that predate PEP 517. "
+              "This is the default for now, but will change in a future version."
+              )
+    )
+
+    parser_build.add_argument('--no-setup-py', action='store_true',
         help=("Don't generate a setup.py file in the sdist. "
               "The sdist will only work with tools that support PEP 517, "
               "but the wheel will still be usable by any compatible tool."
@@ -95,7 +102,14 @@ def main(argv=None):
         help="Select a format to publish. Options: 'wheel', 'sdist'"
     )
 
-    parser_publish.add_argument('--no-setup-py', action='store_false', dest='setup_py',
+    parser_publish.add_argument('--setup-py', action='store_true',
+        help=("Generate a setup.py file in the sdist. "
+              "The sdist will work with older tools that predate PEP 517. "
+              "This is the default for now, but will change in a future version."
+              )
+    )
+
+    parser_publish.add_argument('--no-setup-py', action='store_true',
         help=("Don't generate a setup.py file in the sdist. "
               "The sdist will only work with tools that support PEP 517, "
               "but the wheel will still be usable by any compatible tool."
@@ -148,11 +162,21 @@ def main(argv=None):
         print(clogo.format(version=__version__))
         sys.exit(0)
 
+    def gen_setup_py():
+        if not (args.setup_py or args.no_setup_py):
+            log.info("Adding generated setup.py to sdist by default.")
+            log.info(
+                "This will change in a future version. Pass --[no-]setup-py to "
+                "control it."
+            )
+            return True
+        return args.setup_py
+
     if args.subcmd == 'build':
         from .build import main
         try:
             main(args.ini_file, formats=set(args.format or []),
-                 gen_setup_py=args.setup_py)
+                 gen_setup_py=gen_setup_py())
         except(common.NoDocstringError, common.VCSError, common.NoVersionError) as e:
             sys.exit(e.args[0])
     elif args.subcmd == 'publish':
@@ -161,7 +185,7 @@ def main(argv=None):
         repository = args.repository or args.deprecated_repository
         from .upload import main
         main(args.ini_file, repository, formats=set(args.format or []),
-                gen_setup_py=args.setup_py)
+                gen_setup_py=gen_setup_py())
 
     elif args.subcmd == 'install':
         from .install import Installer