Use uname() instead of CMAKE_SYSTEM

fix #3235

louloulibs/utils/system.cpp

@@ -0,0 +1,21 @@
+#include <logger/logger.hpp>
+#include <utils/system.hpp>
+#include <sys/utsname.h>
+#include <cstring>
+
+using namespace std::string_literals;
+
+namespace utils
+{
+std::string get_system_name()
+{
+  struct utsname uts;
+  const int res = ::uname(&uts);
+  if (res == -1)
+    {
+      log_error("uname failed: ", std::strerror(errno));
+      return "Unknown";
+    }
+  return uts.sysname + " "s + uts.release;
+}
+}