Fix for when there are so many file arguments it creates the Command To Long error (#320)

Author: opbro

experimental/python/wheel.bzl

@@ -98,6 +98,14 @@ def _py_wheel_impl(ctx):
     # Currently this is only the description file (if used).
     other_inputs = []
 
+    # Wrap the inputs into a file to reduce command line length.
+    packageinputfile = ctx.actions.declare_file(ctx.attr.name + '_target_wrapped_inputs.txt')
+    content = ''
+    for input_file in inputs_to_package.to_list():
+        content += _input_file_to_arg(input_file) + '\n'
+    ctx.actions.write(output = packageinputfile, content=content)
+    other_inputs.append(packageinputfile)
+
     args = ctx.actions.args()
     args.add("--name", ctx.attr.distribution)
     args.add("--version", ctx.attr.version)
@@ -107,7 +115,7 @@ def _py_wheel_impl(ctx):
     args.add("--out", outfile.path)
     args.add_all(ctx.attr.strip_path_prefixes, format_each = "--strip_path_prefix=%s")
 
-    args.add_all(inputs_to_package, format_each = "--input_file=%s", map_each = _input_file_to_arg)
+    args.add("--input_file_list", packageinputfile)
 
     extra_headers = []
     if ctx.attr.author:

experimental/rules_python/wheelmaker.py

@@ -242,6 +242,10 @@ def main():
         help="'package_path;real_path' pairs listing "
              "files to be included in the wheel. "
              "Can be supplied multiple times.")
+    contents_group.add_argument(
+        '--input_file_list', action='append',
+        help='A file that has all the input files defined as a list to avoid the long command'
+    )
     contents_group.add_argument(
         '--console_script', action='append',
         help="Defines a 'console_script' entry point. "
@@ -264,6 +268,14 @@ def main():
         input_files = [i.split(';') for i in arguments.input_file]
     else:
         input_files = []
+
+    if arguments.input_file_list:
+        for input_file in arguments.input_file_list:
+            with open(input_file) as _file:
+                input_file_list = _file.read().splitlines()
+            for _input_file in input_file_list:
+                input_files.append(_input_file.split(';'))
+
     all_files = get_files_to_package(input_files)
     # Sort the files for reproducible order in the archive.
     all_files = sorted(all_files.items())