diff -r 8433c87c0f51 -r 78ce93fb46e5 src/glcontext.c
--- a/src/glcontext.c	Tue Apr 22 19:36:27 2025 +0200
+++ b/src/glcontext.c	Wed Apr 23 23:43:45 2025 +0200
@@ -37,15 +37,13 @@
         GLsizei length, const GLchar* message,
         const void* userParam
 ) {
-    cxmutstr buf = cx_asprintf(
-            "source = %d, id = %u, type = %d, severity= %d, message = %.*s",
+    if (type == GL_DEBUG_TYPE_ERROR) {
+        asc_error("OpenGL source = %d, id = %u, type = %d, severity= %d, message = %.*s",
             source, id, type, severity, length, message);
-    if (type == GL_DEBUG_TYPE_ERROR) {
-        asc_error(buf.ptr);
     } else {
-        asc_dprintf("GL debug: %.*s", (int)buf.length, buf.ptr);
+        asc_dprintf("OpenGL source = %d, id = %u, type = %d, severity= %d, message = %.*s",
+            source, id, type, severity, length, message);
     }
-    cx_strfree(&buf);
 }
 
 static int asc_primitives_init(AscGLContext *context) {
@@ -83,9 +81,7 @@
         0, 1, 1, 32,
         0xFF000000, 0x00FF0000, 0x0000FF00, 0x000000FF);
     if (white1x1 == NULL) {
-        // TODO: merge error messages once asc_error allows formatting
-        asc_error("Failed to create surface");
-        asc_error(SDL_GetError());
+        asc_error("Failed to create surface: %s", SDL_GetError());
         return 1;
     }
     SDL_FillRect(white1x1, NULL, 0xFFFFFFFF);
@@ -144,7 +140,7 @@
 
         return true;
     } else {
-        asc_error(glewGetErrorString(err));
+        asc_error("glewInit failed: %s", glewGetErrorString(err));
         SDL_GL_DeleteContext(ctx->glctx);
         return false;
     }