A handler for the OS ABI "GNU/Linux" is not built into this configuration

[William Tambe]

I have ported GNU gdb (GDB) 10.0.50.20200513-git and I am seeing below
errors when loading a core file:

----
warning: A handler for the OS ABI "GNU/Linux" is not built into this
configuration
of GDB.  Attempting to continue with the default IRON settings.

Reading symbols from /mnt/bin/busybox...
"/tmp/cores/busybox.80.647.core": Core file format not supported
----

What support needs to be implemented in GDB in order to prevent above
warnings ? could it also be the reason why "Core file format not
supported" is thrown ?