Replace deprecated `imp` usage with `importlib`

Signed-off-by: Cole Robinson <crobinso@redhat.com>

setup.py

@@ -10,6 +10,7 @@ if sys.version_info.major < 3:
     sys.exit(1)
 
 import glob
+import importlib.util
 import os
 from pathlib import Path
 import shutil
@@ -33,18 +34,14 @@ def _import_buildconfig():
     # A bit of crazyness to import the buildconfig file without importing
     # the rest of virtinst, so the build process doesn't require all the
     # runtime deps to be installed
-    import warnings
-
-    # 'imp' is deprecated. We use it elsewhere though too. Deal with using
-    # the modern replacement when we replace all usage
-    with warnings.catch_warnings():
-        warnings.filterwarnings("ignore", category=DeprecationWarning)
-        import imp
-        buildconfig = imp.load_source('buildconfig', 'virtinst/buildconfig.py')
-        if "libvirt" in sys.modules:
-            raise RuntimeError("Found libvirt in sys.modules. setup.py should "
-                    "not import virtinst.")
-        return buildconfig.BuildConfig
+    spec = importlib.util.spec_from_file_location(
+            'buildconfig', 'virtinst/buildconfig.py')
+    buildconfig = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(buildconfig)
+    if "libvirt" in sys.modules:
+        raise RuntimeError("Found libvirt in sys.modules. setup.py should "
+                "not import virtinst.")
+    return buildconfig.BuildConfig
 
 
 BuildConfig = _import_buildconfig()

tests/__init__.py

@@ -3,7 +3,7 @@
 # This work is licensed under the GNU GPLv2 or later.
 # See the COPYING file in the top-level directory.
 
-import imp
+import importlib
 import os
 
 # Need to do this before any tests or virtinst import
@@ -18,8 +18,9 @@ os.environ.pop("LANGUAGE", None)
 # pylint: disable=wrong-import-position
 from virtinst import buildconfig
 from virtinst import log, reset_logging
+
 # This sets all the cli bits back to their defaults
-imp.reload(buildconfig)
+importlib.reload(buildconfig)
 
 from tests import utils