Rearrange trys to avoid possible undefined vars.

mesonbuild/environment.py

@@ -459,11 +459,11 @@ class Environment:
         for compiler in compilers:
             if isinstance(compiler, str):
                 compiler = [compiler]
+            if 'cl' in compiler or 'cl.exe' in compiler:
+                arg = '/?'
+            else:
+                arg = '--version'
             try:
-                if 'cl' in compiler or 'cl.exe' in compiler:
-                    arg = '/?'
-                else:
-                    arg = '--version'
                 p, out, err = Popen_safe(compiler + [arg])
             except OSError as e:
                 popen_exceptions[' '.join(compiler + [arg])] = e

mesonbuild/wrap/wrap.py

@@ -301,12 +301,13 @@ class Resolver:
             try:
                 import lzma
                 del lzma
+            except ImportError:
+                pass
+            else:
                 try:
                     shutil.register_unpack_format('xztar', ['.tar.xz', '.txz'], shutil._unpack_tarfile, [], "xz'ed tar-file")
                 except shutil.RegistryError:
                     pass
-            except ImportError:
-                pass
         target_dir = os.path.join(self.subdir_root, package.get('directory'))
         if os.path.isdir(target_dir):
             return

mesontest.py

@@ -457,11 +457,11 @@ TIMEOUT: %4d
             return test.name
 
     def run_tests(self, tests):
+        executor = None
+        logfile = None
+        jsonlogfile = None
+        futures = []
         try:
-            executor = None
-            logfile = None
-            jsonlogfile = None
-            futures = []
             numlen = len('%d' % len(tests))
             (logfile, logfilename, jsonlogfile, jsonlogfilename) = self.open_log_files()
             wrap = self.get_wrapper()