Add support for PLATFORMIO_DEFAULT_ENVS system environment variable // Resolve #1967

tests/test_projectconf.py

@@ -74,8 +74,8 @@ def test_real_config(tmpdir):
     with tmpdir.as_cwd():
         config = ProjectConfig(tmpdir.join("platformio.ini").strpath)
     assert config
-    assert len(config.warnings) == 1
-    assert "lib_install" in config.warnings[0]
+    assert len(config.warnings) == 2
+    assert "lib_install" in config.warnings[1]
 
     config.validate(["extra_2", "base"], silent=True)
     with pytest.raises(UnknownEnvNames):