[PATCH v3] kunit: Fix kunit.py run --build_dir='<foo>' fails on "unclean" trees

[Vitor Massaru Iha]

Fix this bug: https://bugzilla.kernel.org/show_bug.cgi?id=205219

For some reason, the environment variable ARCH is used instead of ARCH
passed as an argument, this patch uses a copy of the env, but using
ARCH=um and CROSS_COMPILER='' to avoid this problem.

This patch doesn't change the user's environment variables, avoiding
side effects.

Signed-off-by: Vitor Massaru Iha <vitor@xxxxxxxxxxx>
---
v2:
 - Use the correct next branch

v3:
 - Use torvalds/master branch
 - Use base parameter on git send-email
---
 tools/testing/kunit/kunit_kernel.py | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
index 63dbda2d029f..96216c699fde 100644
--- a/tools/testing/kunit/kunit_kernel.py
+++ b/tools/testing/kunit/kunit_kernel.py
@@ -20,6 +20,7 @@ import kunit_parser
 KCONFIG_PATH = '.config'
 kunitconfig_path = '.kunitconfig'
 BROKEN_ALLCONFIG_PATH = 'tools/testing/kunit/configs/broken_on_uml.config'
+env = dict(os.environ.copy(), ARCH='um', CROSS_COMPILE='')
 
 class ConfigError(Exception):
 	"""Represents an error trying to configure the Linux kernel."""
@@ -41,13 +42,15 @@ class LinuxSourceTreeOperations(object):
 			raise ConfigError(e.output)
 
 	def make_olddefconfig(self, build_dir, make_options):
-		command = ['make', 'ARCH=um', 'olddefconfig']
+		command = ['make', 'olddefconfig']
 		if make_options:
 			command.extend(make_options)
 		if build_dir:
 			command += ['O=' + build_dir]
 		try:
-			subprocess.check_output(command, stderr=subprocess.PIPE)
+			subprocess.check_output(command,
+						stderr=subprocess.PIPE,
+						env=env)
 		except OSError as e:
 			raise ConfigError('Could not call make command: ' + e)
 		except subprocess.CalledProcessError as e:
@@ -57,9 +60,10 @@ class LinuxSourceTreeOperations(object):
 		kunit_parser.print_with_timestamp(
 			'Enabling all CONFIGs for UML...')
 		process = subprocess.Popen(
-			['make', 'ARCH=um', 'allyesconfig'],
+			['make', 'allyesconfig'],
 			stdout=subprocess.DEVNULL,
-			stderr=subprocess.STDOUT)
+			stderr=subprocess.STDOUT,
+			env=env)
 		process.wait()
 		kunit_parser.print_with_timestamp(
 			'Disabling broken configs to run KUnit tests...')
@@ -71,13 +75,13 @@ class LinuxSourceTreeOperations(object):
 			'Starting Kernel with all configs takes a few minutes...')
 
 	def make(self, jobs, build_dir, make_options):
-		command = ['make', 'ARCH=um', '--jobs=' + str(jobs)]
+		command = ['make', '--jobs=' + str(jobs)]
 		if make_options:
 			command.extend(make_options)
 		if build_dir:
 			command += ['O=' + build_dir]
 		try:
-			subprocess.check_output(command)
+			subprocess.check_output(command, env=env)
 		except OSError as e:
 			raise BuildError('Could not call execute make: ' + e)
 		except subprocess.CalledProcessError as e:
@@ -91,7 +95,8 @@ class LinuxSourceTreeOperations(object):
 		with open(outfile, 'w') as output:
 			process = subprocess.Popen([linux_bin] + params,
 						   stdout=output,
-						   stderr=subprocess.STDOUT)
+						   stderr=subprocess.STDOUT,
+						   env=env)
 			process.wait(timeout)
 
 
-- 
2.25.1