Gdbusauth.c:1298:11: error: '%s' directive argument is null

Hellow,

I'm still using Lede 17.01 on mikrotik routerboards.
I have lede installed on Linux Mint 19 and all worked fine, but now I reinstall my computer to newest Linux mint 20.1 and "make" failed with error:

make[8]: Entering directory '/home/riso/lede/build_dir/target-mips_24kc_musl-1.1.16/host/glib-2.50.2/gio'
  CC       libgio_2_0_la-gdbusauth.lo
gdbusauth.c: In function '_g_dbus_auth_run_server':
gdbusauth.c:1298:11: error: '%s' directive argument is null [-Werror=format-overflow=]
 1298 |           debug_print ("SERVER: WaitingForBegin, read '%s'", line);
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors

Can you help me with this?

If you still want to compile year 2017 code, your best bet is some Linux from 2016.
E.g. Ubuntu 16.04 LTS in virtualbox.

Old source might not be compatible with the current host build tools...