Skip FeatureNew checks when project() has not been parsed

Fixes https://github.com/mesonbuild/meson/issues/3944

mesonbuild/interpreterbase.py

@@ -172,6 +172,9 @@ class FeatureCheckBase:
 
     @staticmethod
     def get_target_version(subproject):
+        # Don't do any checks if project() has not been parsed yet
+        if subproject not in mesonlib.project_meson_versions:
+            return ''
         return mesonlib.project_meson_versions[subproject]
 
     def use(self, subproject):

test cases/common/38 run program/get-version.py

@@ -0,0 +1,3 @@
+#!/usr/bin/env python3
+
+print('1.2')

test cases/common/38 run program/meson.build

@@ -1,4 +1,4 @@
-project('run command', 'c')
+project('run command', version : run_command('get-version.py', check : true).stdout().strip())
 
 if build_machine.system() == 'windows'
   c = run_command('cmd', '/c', 'echo', 'hello')