fix: make requires_file additive and fix Requires-Dist bug

python/packaging.bzl

@@ -189,7 +189,7 @@ def _py_wheel_impl(ctx):
     if ctx.attr.python_requires:
         metadata_contents.append("Requires-Python: %s" % ctx.attr.python_requires)
 
-    if len(ctx.attr.requires) == 0 and ctx.attr.requires_file:
+    if ctx.attr.requires_file:
         requires_file = ctx.file.requires_file
         args.add("--requires_file", requires_file)
         other_inputs.append(requires_file)
@@ -358,7 +358,7 @@ _requirement_attrs = {
                "for details and examples of the format of this argument."),
     ),
     "requires_file": attr.label(
-        doc = "Requirements file for list of requirements for this package. If set `requires`, this flag will be ignored.",
+        doc = "Requirements file for list of requirements for this package, which will be additive after `requires`",
         allow_single_file = True,
     ),
 }

tools/wheelmaker.py

@@ -261,8 +261,7 @@ def parse_args() -> argparse.Namespace:
     metadata_group.add_argument(
         "--requires_file",
         type=Path,
-        default="",
-        help="Requirements file for list of requirements for this package",
+        help="Requirements file for list of requirements for this package, which will be additive after `requires`",
     )
 
     output_group = parser.add_argument_group("Output file location")
@@ -406,7 +405,8 @@ def main() -> None:
 
         if arguments.requires_file:
             with open(arguments.requires_file) as fp:
-                metadata += "\n" + fp.read().strip().split("\n")
+                additive_requires_list = ["Requires-Dist: {}".format(line) for line in fp.read().strip().split("\n")]
+                metadata += "\n" + "\n".join(additive_requires_list)
         maker.add_metadata(metadata=metadata, description=description)
 
         if arguments.entry_points_file: