diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 5b4d0263..ddf00cd3 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -3,6 +3,7 @@ enable_testing()
 include( GoogleTest )
 
 set ( TESTS
+      auxiliary.cpp
       interface_c.cpp )
 
 
diff --git a/test/auxiliary.cpp b/test/auxiliary.cpp
new file mode 100644
index 00000000..1293647e
--- /dev/null
+++ b/test/auxiliary.cpp
@@ -0,0 +1,86 @@
+#include <gtest/gtest.h>
+
+
+extern "C" {
+    int show_debug_output();
+    void update_depot_path(const char * project_directory, const char * depot_path);
+}
+
+// Julia project path defined via cmake
+const char * julia_project_path = JULIA_PROJECT_PATH;
+
+const char* default_depot_path = "julia-depot";
+
+
+TEST(AuxiliaryTest, DebugOutput) {
+
+    const char * envvar = "LIBTRIXI_DEBUG";
+
+    // environment variable not set -> no debug output
+    unsetenv(envvar);
+    EXPECT_EQ( show_debug_output(), 0 );
+
+    // environment variable set to "all" -> debug output
+    setenv(envvar, "all", /*overwrite*/ 1 );
+    EXPECT_EQ( show_debug_output(), 1 );
+
+    // environment variable set to "c" -> debug output
+    setenv(envvar, "c", /*overwrite*/ 1 );
+    EXPECT_EQ( show_debug_output(), 1 );
+
+    // environment variable set to "julia" -> no debug output
+    setenv(envvar, "julia", /*overwrite*/ 1 );
+    EXPECT_EQ( show_debug_output(), 0 );
+}
+
+
+TEST(AuxiliaryTest, DepotPath) {
+
+    const char * depot_envvar = "JULIA_DEPOT_PATH";
+    const char * custom_depot_path = "/tmp/julia-depot";
+
+    // unset depot path environment variable
+    unsetenv(depot_envvar);
+
+    // let it be set explictly and check
+    update_depot_path( julia_project_path, custom_depot_path );
+    EXPECT_STREQ( getenv(depot_envvar), custom_depot_path );
+
+    // unset depot path environment variable
+    unsetenv(depot_envvar);
+
+    // let it be set to default location and check
+    update_depot_path( julia_project_path, NULL );
+    std::string expected_depot_path( julia_project_path );
+    expected_depot_path.append("/");
+    expected_depot_path.append( default_depot_path );
+    EXPECT_STREQ( getenv(depot_envvar), expected_depot_path.c_str() );
+
+    // unset depot path environment variable
+    unsetenv(depot_envvar);
+
+    // be evil
+    const char * garbage = "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long"
+                           "this_string_is_just_way_toooooooooooooooooooo_long";
+    EXPECT_DEATH( update_depot_path( garbage, NULL ),
+                  "buffer size not sufficient for depot path construction");
+}