Description: Use python3 in tests
 Some upstream tests for the custom `process` module call the python interpreter
 in a subprocess. In Debian, where we only build for python3, "python" is not
 available during build and thus makes those tests fail. This patch replaces
 "python" with "python3" where applicable.
Author: Lukas Puehringer <lukas.puehringer@nyu.edu>
Forwarded: not-needed

--- python-securesystemslib-0.16.0.orig/tests/test_process.py
+++ python-securesystemslib-0.16.0/tests/test_process.py
@@ -38,7 +38,7 @@ class Test_Process(unittest.TestCase):
 
     stdin_file = open(path)
     cmd = \
-        "python -c \"import sys; assert(sys.stdin.read() == '{}')\""
+        "python3 -c \"import sys; assert(sys.stdin.read() == '{}')\""
 
     # input is used in favor of stdin
     securesystemslib.process.run(cmd.format("use input kwarg"),
@@ -57,7 +57,7 @@ class Test_Process(unittest.TestCase):
   def test_run_duplicate_streams(self):
     """Test output as streams and as returned.  """
     # Command that prints 'foo' to stdout and 'bar' to stderr.
-    cmd = ("python -c \""
+    cmd = ("python3 -c \""
         "import sys;"
         "sys.stdout.write('foo');"
         "sys.stderr.write('bar');\"")
@@ -101,7 +101,7 @@ class Test_Process(unittest.TestCase):
 
   def test_run_cmd_arg_return_code(self):
     """Test command arg as string and list using return code. """
-    cmd_str = ("python -c \""
+    cmd_str = ("python3 -c \""
         "import sys;"
         "sys.exit(100)\"")
     cmd_list = shlex.split(cmd_str)
@@ -117,7 +117,7 @@ class Test_Process(unittest.TestCase):
   def test_run_duplicate_streams_timeout(self):
     """Test raise TimeoutExpired. """
     with self.assertRaises(securesystemslib.process.subprocess.TimeoutExpired):
-      securesystemslib.process.run_duplicate_streams("python --version",
+      securesystemslib.process.run_duplicate_streams("python3 --version",
           timeout=-1)