Backport function tests from centos stream

tests/functions_test/Makefile

@@ -72,4 +72,4 @@ $(METADATA): Makefile
 	@echo "RunFor:       $(PACKAGE_NAME)" >> $(METADATA)
 	@echo "Requires:     $(PACKAGE_NAME)" >> $(METADATA)
 
-	rhts-lint $(METADATA)
+	rhts-lint $(METADATA)

tests/functions_test/dmpd_library.py

@@ -16,6 +16,8 @@
 
 """dmpd_library.py: Complete library providing functionality for device-mapper-persistent-data upstream test."""
 
+from __future__ import print_function
+
 import platform
 from os.path import expanduser
 import re #regex
@@ -25,7 +27,6 @@ import time
 import fileinput
 # TODO: Is this really necessary? Unlikely we will run into python2 in rawhide
 # again...
-from __future__ import print_function
 
 
 def _print(string):
@@ -55,7 +56,7 @@ def run(cmd, return_output=False, verbose=True, force_flush=False):
         date = "date \"+%Y-%m-%d %H:%M:%S\""
         p = subprocess.Popen(date, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
         stdout, stderr = p.communicate()
-        stdout = stdout.rstrip("\n")
+        stdout = stdout.decode('ascii', 'ignore').rstrip("\n")
         _print("INFO: [%s] Running: '%s'..." % (stdout, cmd))
 
     #enabling shell=True, because was the only way I found to run command with '|'
@@ -77,7 +78,7 @@ def run(cmd, return_output=False, verbose=True, force_flush=False):
 
     retcode = p.returncode
 
-    output = stdout + stderr
+    output = stdout.decode('ascii', 'ignore') + stderr.decode('ascii', 'ignore')
 
     #remove new line from last line
     output = output.rstrip()