diff --git a/git_fleximod/gitinterface.py b/git_fleximod/gitinterface.py
index eff155d..4d4c4f4 100644
--- a/git_fleximod/gitinterface.py
+++ b/git_fleximod/gitinterface.py
@@ -1,4 +1,5 @@
 import os
+import sys
 from . import utils
 
 class GitInterface:
@@ -26,7 +27,10 @@ def __init__(self, repo_path, logger):
     def _git_command(self, operation, *args):
         self.logger.info(operation)
         if self._use_module and operation != "submodule":
-            return getattr(self.repo.git, operation)(*args)
+            try:
+                return getattr(self.repo.git, operation)(*args)
+            except Exception as e:
+                sys.exit(e)
         else:
             return ["git", "-C", self.repo_path, operation] + list(args)
 
@@ -42,7 +46,10 @@ def git_operation(self, operation, *args, **kwargs):
         command = self._git_command(operation, *args)
         self.logger.info(command)
         if isinstance(command, list):
-            return utils.execute_subprocess(command, output_to_caller=True)
+            try:
+                return utils.execute_subprocess(command, output_to_caller=True)
+            except Exception as e:
+                sys.exit(e)
         else:
             return command
 
diff --git a/poetry.lock b/poetry.lock
index 6c31fac..b59ed39 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -404,6 +404,17 @@ files = [
 dev = ["pre-commit", "tox"]
 testing = ["pytest", "pytest-benchmark"]
 
+[[package]]
+name = "pyfakefs"
+version = "5.3.5"
+description = "pyfakefs implements a fake file system that mocks the Python file system modules."
+optional = false
+python-versions = ">=3.7"
+files = [
+    {file = "pyfakefs-5.3.5-py3-none-any.whl", hash = "sha256:751015c1de94e1390128c82b48cdedc3f088bbdbe4bc713c79d02a27f0f61e69"},
+    {file = "pyfakefs-5.3.5.tar.gz", hash = "sha256:7cdc500b35a214cb7a614e1940543acc6650e69a94ac76e30f33c9373bd9cf90"},
+]
+
 [[package]]
 name = "pygments"
 version = "2.17.2"
@@ -679,4 +690,4 @@ testing = ["big-O", "jaraco.functools", "jaraco.itertools", "more-itertools", "p
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.8"
-content-hash = "f20e29bada880bbb0aad20d2a7ac282d09c3e89d4aac06072cb82a9157f4023a"
+content-hash = "25ee2ae1d74abedde3a6637a60d4a3095ea5cf9731960875741bbc2ba84a475d"
diff --git a/pyproject.toml b/pyproject.toml
index f5828a5..6d0fa42 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,7 +14,7 @@ packages = [
 ]
 
 [tool.poetry.scripts]
-git-fleximod = "git_fleximod.git-fleximod:main"
+git-fleximod = "git_fleximod.git_fleximod:main"
 fsspec = "fsspec.fuse:main"
 
 [tool.poetry.dependencies]
@@ -24,6 +24,7 @@ sphinx = "^5.0.0"
 fsspec = "^2023.12.2"
 wheel = "^0.42.0"
 pytest = "^8.0.0"
+pyfakefs = "^5.3.5"
 
 [tool.poetry.urls]
 "Bug Tracker" = "https://github.com/jedwards4b/git-fleximod/issues"
diff --git a/tests/test_import.py b/tests/test_a_import.py
similarity index 100%
rename from tests/test_import.py
rename to tests/test_a_import.py
diff --git a/tests/test_checkout.py b/tests/test_checkout.py
new file mode 100644
index 0000000..7915876
--- /dev/null
+++ b/tests/test_checkout.py
@@ -0,0 +1,32 @@
+import pytest
+from pathlib import Path
+
+def test_basic_checkout(git_fleximod, test_repo):
+    # Prepare a simple .gitmodules
+    
+    gitmodules_content = """
+    [submodule "test_submodule"]
+        path = modules/test
+        url = https://github.com/ESMCI/mpi-serial.git
+        fxtag = MPIserial_2.4.0
+        fxurl = https://github.com/ESMCI/mpi-serial.git
+        fxrequired = T:T
+    """
+    (test_repo / ".gitmodules").write_text(gitmodules_content)
+    
+    # Run the command
+    result = git_fleximod("checkout")
+
+    # Assertions
+    assert result.returncode == 0
+    assert Path(test_repo / "modules/test").exists()   # Did the submodule directory get created?
+
+    status = git_fleximod("status")
+
+    assert "test_submodule d82ce7c is out of sync with .gitmodules MPIserial_2.4.0" in status.stdout
+
+    result = git_fleximod("update")
+    assert result.returncode == 0
+
+    status = git_fleximod("status")
+    assert "test_submodule at tag MPIserial_2.4.0" in status.stdout
diff --git a/tests/test_sparse_checkout.py b/tests/test_sparse_checkout.py
new file mode 100644
index 0000000..0633802
--- /dev/null
+++ b/tests/test_sparse_checkout.py
@@ -0,0 +1,38 @@
+import pytest
+from shutil import rmtree
+from pathlib import Path
+from git_fleximod.gitinterface import GitInterface
+
+def test_sparse_checkout(git_fleximod, test_repo_base):
+    # Prepare a simple .gitmodules
+    gitmodules_content = (test_repo_base / ".gitmodules").read_text() + """
+    [submodule "test_sparse_submodule"]
+        path = modules/sparse_test
+        url = https://github.com/ESMCI/mpi-serial.git
+        fxtag = MPIserial_2.5.0
+        fxurl = https://github.com/ESMCI/mpi-serial.git
+        fxsparse = ../.sparse_file_list
+    """
+    (test_repo_base / ".gitmodules").write_text(gitmodules_content)
+
+    # Add the sparse checkout file
+    sparse_content = """m4
+"""
+    (test_repo_base / "modules" / ".sparse_file_list").write_text(sparse_content)
+
+    result = git_fleximod("checkout")
+    
+    # Assertions
+    assert result.returncode == 0
+    assert Path(test_repo_base / "modules/sparse_test").exists()   # Did the submodule directory get created?
+    assert Path(test_repo_base /  "modules/sparse_test/m4").exists()   # Did the submodule sparse directory get created?
+    assert not Path(test_repo_base /  "modules/sparse_test/README").exists()   # Did only the submodule sparse directory get created?
+    status = git_fleximod("status test_sparse_submodule")
+
+    assert "test_sparse_submodule at tag MPIserial_2.5.0" in status.stdout
+
+    result = git_fleximod("update")
+    assert result.returncode == 0
+
+    status = git_fleximod("status test_sparse_submodule")
+    assert "test_sparse_submodule at tag MPIserial_2.5.0" in status.stdout