diff --git a/install/install_ibcdfo.sh b/install/install_ibcdfo.sh
index efd5f6dcb..0ed790f01 100644
--- a/install/install_ibcdfo.sh
+++ b/install/install_ibcdfo.sh
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-git clone --recurse-submodules -b develop https://github.com/POptUS/IBCDFO.git
+git clone --recurse-submodules -b main https://github.com/POptUS/IBCDFO.git
 pushd IBCDFO/minq/py/minq5/
 export PYTHONPATH="$PYTHONPATH:$(pwd)"
 echo "PYTHONPATH=$PYTHONPATH" >> $GITHUB_ENV
diff --git a/libensemble/executors/executor.py b/libensemble/executors/executor.py
index d9cf6f428..dca58deaf 100644
--- a/libensemble/executors/executor.py
+++ b/libensemble/executors/executor.py
@@ -673,10 +673,16 @@ def set_worker_info(self, comm=None, workerid=None) -> None:
         self.workerID = workerid
         self.comm = comm
 
-    def _check_app_exists(self, full_path: str) -> None:
+    def _check_app_exists(self, app: Application) -> None:
         """Allows submit function to check if app exists and error if not"""
-        if not os.path.isfile(full_path):
-            raise ExecutorException(f"Application does not exist {full_path}")
+        if app.precedent is not None:
+            # Could be a container call in precedent. In that case,
+            # the executable is not available on the host system and
+            # we just forward what the user provided.
+            return
+
+        if not os.path.isfile(app.full_path):
+            raise ExecutorException(f"Application does not exist {app.full_path}")
 
     def submit(
         self,
@@ -745,7 +751,7 @@ def submit(
         task = Task(app, app_args, default_workdir, stdout, stderr, self.workerID, dry_run)
 
         if not dry_run:
-            self._check_app_exists(task.app.full_path)
+            self._check_app_exists(task.app)
 
         runline = task.app.app_cmd.split()
         if task.app_args is not None:
diff --git a/libensemble/executors/mpi_executor.py b/libensemble/executors/mpi_executor.py
index 9b167ddaa..114144291 100644
--- a/libensemble/executors/mpi_executor.py
+++ b/libensemble/executors/mpi_executor.py
@@ -317,7 +317,7 @@ def submit(
         task = Task(app, app_args, default_workdir, stdout, stderr, self.workerID, dry_run)
 
         if not dry_run:
-            self._check_app_exists(task.app.full_path)
+            self._check_app_exists(task.app)
 
         if stage_inout is not None:
             logger.warning("stage_inout option ignored in this " "executor - runs in-place")
diff --git a/libensemble/tests/unit_tests/test_executor.py b/libensemble/tests/unit_tests/test_executor.py
index df5c8cc32..830c05ce3 100644
--- a/libensemble/tests/unit_tests/test_executor.py
+++ b/libensemble/tests/unit_tests/test_executor.py
@@ -909,8 +909,8 @@ def test_non_existent_app():
 
     try:
         w_exctr.submit(app_name="nonexist")
-    except ExecutorException as e:
-        assert e.args[0] == "Application does not exist simdir/non_exist.x"
+    except FileNotFoundError as e:
+        assert e.filename == "simdir/non_exist.x"
     else:
         assert 0
 
@@ -930,8 +930,8 @@ def test_non_existent_app_mpi():
 
     try:
         w_exctr.submit(app_name="nonexist")
-    except ExecutorException as e:
-        assert e.args[0] == "Application does not exist simdir/non_exist.x"
+    except MPIResourcesException:
+        pass
     else:
         assert 0