add homebrew location to default DB search path

src/rawtoaces_core/rawtoaces_core.cpp

@@ -263,8 +263,16 @@ SpectralSolver::collect_data_files( const std::string &type ) const
         }
         else
         {
-            std::cerr << "Warning: Database location '" << directory
-                      << "' is not a directory." << std::endl;
+            if ( std::filesystem::exists( directory ) )
+            {
+                std::cerr << "Warning: Database location '" << directory
+                          << "' is not a directory." << std::endl;
+            }
+            else
+            {
+                std::cerr << "Warning: Database location '" << directory
+                          << "' does not exist." << std::endl;
+            }
         }
     }
     return result;

src/rawtoaces_util/image_converter.cpp

@@ -223,6 +223,12 @@ std::vector<std::string> database_paths( const std::string &override_path = "" )
 #if defined( WIN32 ) || defined( WIN64 )
     const std::string separator    = ";";
     const std::string default_path = ".";
+#elif defined( __APPLE__ )
+    const std::string separator   = ":";
+    const std::string legacy_path = "/usr/local/include/rawtoaces/data";
+    const std::string default_path =
+        "/usr/local/share/rawtoaces/data" + separator +
+        "/opt/homebrew/share/rawtoaces/data" + separator + legacy_path;
 #else
     const std::string separator   = ":";
     const std::string legacy_path = "/usr/local/include/rawtoaces/data";

tests/test_image_converter.cpp

@@ -414,10 +414,15 @@ void test_database_paths_default()
     OIIO_CHECK_EQUAL( paths.empty(), false );
 
 // On Unix systems, should have both new and legacy paths
-#ifdef WIN32
+#if defined( WIN32 )
     // On Windows, should have just the current directory
     OIIO_CHECK_EQUAL( paths.size(), 1 );
     OIIO_CHECK_EQUAL( paths[0], "." );
+#elif defined( __APPLE__ )
+    OIIO_CHECK_EQUAL( paths.size(), 3 );
+    OIIO_CHECK_EQUAL( paths[0], "/usr/local/share/rawtoaces/data" );
+    OIIO_CHECK_EQUAL( paths[1], "/opt/homebrew/share/rawtoaces/data" );
+    OIIO_CHECK_EQUAL( paths[2], "/usr/local/include/rawtoaces/data" );
 #else
     OIIO_CHECK_EQUAL( paths.size(), 2 );
     OIIO_CHECK_EQUAL( paths[0], "/usr/local/share/rawtoaces/data" );
@@ -1501,6 +1506,60 @@ void test_database_location_not_directory_warning()
     std::filesystem::remove( file_path );
 }
 
+/// Tests that a warning is issued when a database location path does not exist.
+void test_database_location_missing_warning()
+{
+    std::cout << "\n" << __FUNCTION__ << std::endl;
+
+    // Create test directory
+    TestFixture fixture;
+    auto       &test_dir =
+        fixture.with_camera( "Blackmagic", "Cinema Camera" ).build();
+
+    std::filesystem::path directory_path =
+        std::filesystem::temp_directory_path() / "missing_directory";
+
+    // Create a mock ImageSpec with camera metadata
+    auto image_spec =
+        ImageSpecBuilder().camera( "Blackmagic", "Cinema Camera" ).build();
+
+    // Configure settings with missing directory as database location
+    ImageConverter::Settings settings;
+    settings.database_directories = { directory_path.string(),
+                                      test_dir.get_database_path() };
+    settings.illuminant           = ""; // Empty to trigger auto-detection
+    settings.verbosity            = 1;
+
+    // Make sure the transform is not in the cache, otherwise DB look up
+    // will no be triggered.
+    settings.disable_cache = true;
+
+    // Provide WB_multipliers
+    std::vector<double>              WB_multipliers = { 1.5, 1.0, 1.2, 1.0 };
+    std::vector<std::vector<double>> IDT_matrix;
+    std::vector<std::vector<double>> CAT_matrix;
+
+    bool        success;
+    std::string error_message;
+    std::string output = capture_stderr( [&]() {
+        // This should succeed (using the valid database path)
+        // but should warn about the file path not being a directory
+        success = prepare_transform_spectral(
+            image_spec,
+            settings,
+            WB_multipliers,
+            IDT_matrix,
+            CAT_matrix,
+            error_message );
+    } );
+
+    OIIO_CHECK_ASSERT( success );
+
+    // Assert on expected warning
+    ASSERT_CONTAINS( output, "Warning: Database location '" );
+    ASSERT_CONTAINS( output, "' does not exist." );
+}
+
 /// Tests that spectral data can be loaded using an absolute file path
 void test_load_spectral_data_absolute_path()
 {
@@ -2979,6 +3038,7 @@ int main( int, char ** )
         test_invalid_blackbody_cct_exits();
         test_auto_detect_illuminant_with_wb_multipliers();
         test_database_location_not_directory_warning();
+        test_database_location_missing_warning();
         test_load_spectral_data_absolute_path();
         test_illuminant_file_load_failure();
         test_illuminant_type_mismatch();