diff --git a/lib/spack/spack/test/util/file_cache.py b/lib/spack/spack/test/util/file_cache.py
index 024ce329b31..1b28cd760d7 100644
--- a/lib/spack/spack/test/util/file_cache.py
+++ b/lib/spack/spack/test/util/file_cache.py
@@ -32,6 +32,27 @@ def test_write_and_read_cache_file(file_cache):
         assert text == "foobar\n"
 
 
+@pytest.mark.skipif(sys.platform == "win32", reason="Locks not supported on Windows")
+def test_failed_write_and_read_cache_file(file_cache):
+    """Test failing to write then attempting to read a cached file."""
+    with pytest.raises(RuntimeError, match=r"^foobar$"):
+        with file_cache.write_transaction("test.yaml") as (old, new):
+            assert old is None
+            assert new is not None
+            raise RuntimeError("foobar")
+
+    # Cache dir should have exactly one (lock) file
+    assert os.listdir(file_cache.root) == [".test.yaml.lock"]
+
+    # File does not exist
+    assert not file_cache.init_entry("test.yaml")
+
+    # Attempting to read will cause a FileNotFoundError
+    with pytest.raises(FileNotFoundError, match=r"test\.yaml"):
+        with file_cache.read_transaction("test.yaml"):
+            pass
+
+
 def test_write_and_remove_cache_file(file_cache):
     """Test two write transactions on a cached file. Then try to remove an
     entry from it.
diff --git a/lib/spack/spack/util/file_cache.py b/lib/spack/spack/util/file_cache.py
index 759d150045a..dc89afdde73 100644
--- a/lib/spack/spack/util/file_cache.py
+++ b/lib/spack/spack/util/file_cache.py
@@ -144,8 +144,7 @@ def __exit__(cm, type, value, traceback):
                 cm.tmp_file.close()
 
                 if value:
-                    # remove tmp on exception & raise it
-                    shutil.rmtree(cm.tmp_filename, True)
+                    os.remove(cm.tmp_filename)
 
                 else:
                     rename(cm.tmp_filename, cm.orig_filename)