Try static for windows `handle_ctrlc`.
@@ -28,7 +28,7 @@ int osqp_is_interrupted(void) {
#elif defined IS_WINDOWS
static int int_detected;
-BOOL WINAPI handle_ctrlc(DWORD dwCtrlType) {
+static BOOL WINAPI handle_ctrlc(DWORD dwCtrlType) {
if (dwCtrlType != CTRL_C_EVENT) return FALSE;
int_detected = 1;
