Do warning if another queue system is configured

src/ert/config/queue_config.py

@@ -62,8 +62,8 @@ def from_dict(cls, config_dict: ConfigDict) -> QueueConfig:
             if queue_system != selected_queue_system:
                 warnings.warn(
                     ConfigWarning.with_context(
-                        f"Setting '{option_name}'for {queue_system.name} but "
-                        f"{selected_queue_system.name} is selected. ",
+                        f"Setting '{option_name}' for {queue_system.name} but "
+                        f"{selected_queue_system.name} is selected.",
                         option_name,
                     ),
                     stacklevel=1,

tests/unit_tests/config/test_queue_config.py

@@ -4,7 +4,13 @@
 import pytest
 from hypothesis import given
 
-from ert.config import ConfigValidationError, ErtConfig, QueueConfig, QueueSystem
+from ert.config import (
+    ConfigValidationError,
+    ConfigWarning,
+    ErtConfig,
+    QueueConfig,
+    QueueSystem,
+)
 from ert.job_queue import Driver
 
 
@@ -192,3 +198,17 @@ def test_wrong_config_option_types(queue_system, queue_option, queue_value, err_
 
     with pytest.raises(ConfigValidationError, match=err_msg):
         ErtConfig.from_file(filename)
+
+
+@pytest.mark.usefixtures("use_tmpdir")
+def test_that_configuring_another_queue_system_gives_warning():
+    filename = "config.ert"
+    with open(filename, "w", encoding="utf-8") as f:
+        f.write("NUM_REALIZATIONS 1\n")
+        f.write(f"QUEUE_SYSTEM LSF\n")
+        f.write(f"QUEUE_OPTION SLURM SQUEUE_TIMEOUT 2\n")
+
+    with pytest.warns(
+        ConfigWarning, match="Setting 'SQUEUE_TIMEOUT' for SLURM but LSF is selected."
+    ):
+        ErtConfig.from_file(filename)