Move python version check as first thing

meson.py

@@ -15,6 +15,15 @@
 # limitations under the License.
 
 import sys
+
+# Check python version before importing anything else, we might have an older
+# Python that would error on f-string syntax for example.
+if sys.version_info < (3, 7):
+    print('Meson works correctly only with python 3.7+.')
+    print('You have python {}.'.format(sys.version))
+    print('Please update your environment')
+    sys.exit(1)
+
 from pathlib import Path
 
 # If we're run uninstalled, add the script directory to sys.path to ensure that

mesonbuild/mesonmain.py

@@ -209,12 +209,6 @@ def ensure_stdout_accepts_unicode():
         sys.stdout.reconfigure(errors='surrogateescape')
 
 def run(original_args, mainfile):
-    if sys.version_info < (3, 7):
-        print('Meson works correctly only with python 3.7+.')
-        print(f'You have python {sys.version}.')
-        print('Please update your environment')
-        return 1
-
     if sys.version_info >= (3, 10) and os.environ.get('MESON_RUNNING_IN_PROJECT_TESTS'):
         # workaround for https://bugs.python.org/issue34624
         import warnings