Better error message on library loading failure

Author: thierry-martinez

pyml_stubs.c

@@ -39,7 +39,13 @@ open_library(const char *filename)
     return LoadLibrary(filename);
 }
 
-void
+static char *
+get_library_error()
+{
+    return "Unable to load library";
+}
+
+static void
 close_library(library_t library)
 {
     if (!FreeLibrary(library)) {
@@ -90,6 +96,12 @@ open_library(const char *filename)
     return dlopen(filename, RTLD_LAZY | RTLD_GLOBAL);
 }
 
+static char *
+get_library_error()
+{
+    return dlerror();
+}
+
 void
 close_library(library_t filename)
 {
@@ -660,7 +672,7 @@ py_load_library(value filename_ocaml, value debug_build_ocaml)
         const char *filename = String_val(Field(filename_ocaml, 0));
         library = open_library(filename);
         if (!library) {
-            failwith("Library not found");
+            failwith(get_library_error());
         }
     }
     else {