Avoid forward model crash after MPI NOSIM E100 run

This fixes a regression from 2453a2c.

src/ert/resources/forward_models/res/script/ecl_run.py

@@ -12,7 +12,7 @@
 from contextlib import contextmanager
 from pathlib import Path
 from random import random
-from typing import List
+from typing import List, Optional
 
 import resfo
 from ecl_config import EclConfig, EclrunConfig, Simulator
@@ -157,7 +157,7 @@ def pushd(run_path):
     os.chdir(starting_directory)
 
 
-def find_unsmry(basepath: Path) -> Path:
+def find_unsmry(basepath: Path) -> Optional[Path]:
     def _is_unsmry(base: str, path: str) -> bool:
         if "." not in path:
             return False
@@ -173,7 +173,7 @@ def _is_unsmry(base: str, path: str) -> bool:
         filter(lambda x: _is_unsmry(base, x), os.listdir(dir or "."))
     )
     if not candidates:
-        raise ValueError(f"Could not find any unsmry matching case path {basepath}")
+        return None
     if len(candidates) > 1:
         raise ValueError(
             f"Ambiguous reference to unsmry in {basepath}, could be any of {candidates}"

tests/ert/unit_tests/resources/test_ecl_run_new_config.py

@@ -153,6 +153,53 @@ def test_forward_model_cmd_line_api_works(source_root):
     assert Path("SPE1.OK").exists()
 
 
+@pytest.mark.integration_test
+@pytest.mark.requires_eclipse
+@pytest.mark.usefixtures("use_tmpdir", "init_eclrun_config")
+def test_ecl_run_on_parallel_deck(source_root):
+    deck = (source_root / "test-data/ert/eclipse/SPE1.DATA").read_text(encoding="utf-8")
+    deck = deck.replace("TITLE", "PARALLEL\n  2 /\n\nTITLE")
+    Path("SPE1.DATA").write_text(deck, encoding="utf-8")
+    ecl_run.run(
+        ecl_config.Ecl100Config(), ["SPE1.DATA", "--version=2019.3", "--num-cpu=2"]
+    )
+    assert Path("SPE1.OK").exists()
+
+
+@pytest.mark.integration_test
+@pytest.mark.requires_eclipse
+@pytest.mark.usefixtures("use_tmpdir", "init_eclrun_config")
+def test_eclrun_on_nosim(source_root):
+    deck = (source_root / "test-data/ert/eclipse/SPE1.DATA").read_text(encoding="utf-8")
+    deck = deck.replace("TITLE", "NOSIM\n\nTITLE")
+    Path("SPE1.DATA").write_text(deck, encoding="utf-8")
+    ecl_run.run(ecl_config.Ecl100Config(), ["SPE1.DATA", "--version=2019.3"])
+    assert Path("SPE1.OK").exists()
+    assert not Path("SPE1.UNSMRY").exists()
+
+
+@pytest.mark.integration_test
+@pytest.mark.requires_eclipse
+@pytest.mark.usefixtures("use_tmpdir", "init_eclrun_config")
+def test_await_completed_summary_file_times_out_on_nosim_with_mpi(source_root):
+    minimum_duration = 15  # This is max_wait in the await function tested
+    deck = (source_root / "test-data/ert/eclipse/SPE1.DATA").read_text(encoding="utf-8")
+    deck = deck.replace("TITLE", "NOSIM\n\nPARALLEL\n 2 /\n\nTITLE")
+    Path("SPE1.DATA").write_text(deck, encoding="utf-8")
+    start_time = time.time()
+    ecl_run.run(
+        ecl_config.Ecl100Config(), ["SPE1.DATA", "--version=2019.3", "--num-cpu=2"]
+    )
+    end_time = time.time()
+    assert Path("SPE1.OK").exists()
+    assert not Path(
+        "SPE1.UNSMRY"
+    ).exists(), "A nosim run should not produce an unsmry file"
+    assert (
+        end_time - start_time > minimum_duration
+    ), "timeout in await_completed not triggered"
+
+
 @pytest.mark.integration_test
 @pytest.mark.requires_eclipse
 @pytest.mark.usefixtures("use_tmpdir", "init_eclrun_config")