Intel's oneapi C compiler not producing debug information

Question

I have some simple code

#include <stdio.h>
#include <stdlib.h>

int main()
{
        printf("Hello world\n");
        return EXIT_SUCCESS;
}

I would like to debug it so I compile like so

icl.exe /Z7 /debug:all /Od main.c -o test.exe

I then run the debugger

gdb-oneapi

but when I load the file I get the following error:

(gdb) file test.exe
Reading symbols from test.exe...
(No debugging symbols found in test.exe)

Am I missing some important flag?