Remove unused build() argument

src/pip/_internal/commands/install.py

@@ -355,7 +355,6 @@ class InstallCommand(RequirementCommand):
 
                 _, build_failures = build(
                     reqs_to_build,
-                    should_unpack=True,
                     wheel_cache=wheel_cache,
                     build_options=[],
                     global_options=[],

src/pip/_internal/commands/wheel.py

@@ -168,7 +168,6 @@ class WheelCommand(RequirementCommand):
                 # build wheels
                 build_successes, build_failures = build(
                     reqs_to_build,
-                    should_unpack=False,
                     wheel_cache=wheel_cache,
                     build_options=options.build_options or [],
                     global_options=options.global_options or [],

src/pip/_internal/wheel_builder.py

@@ -260,7 +260,6 @@ def _clean_one_legacy(req, global_options):
 
 def build(
     requirements,  # type: Iterable[InstallRequirement]
-    should_unpack,  # type: bool
     wheel_cache,  # type: WheelCache
     build_options,  # type: List[str]
     global_options,  # type: List[str]
@@ -269,9 +268,6 @@ def build(
     # type: (...) -> BuildResult
     """Build wheels.
 
-    :param should_unpack: If True, after building the wheel, unpack it
-        and replace the sdist with the unpacked version in preparation
-        for installation.
     :return: The list of InstallRequirement that succeeded to build and
         the list of InstallRequirement that failed to build.
     """
@@ -282,9 +278,6 @@ def build(
     if not requirements:
         return [], []
 
-    # TODO by @pradyunsg
-    # Should break up this method into 2 separate methods.
-
     # Build the wheels.
     logger.info(
         'Building wheels for collected packages: %s',