The following invalid code with a cyclic dependency consumes all ressources on my Linux machine. It may make sense to limit the virtual memory for reproducing with ifort/ifx 21.3:
subroutine s(x) implicit character (a-z) character(len=len(y)+1) :: x character(len=len(x)+1) :: y end
You have been warned...
I didn't try compiling on Linux; I didn't want to hang my machine.
I did try it on my Windows laptop since the power button is handy. No hang, no running out of memory! I did get an ICE.
I filed a bug for you, CMPLRIL0-34117. I'll let you know when it's fixed and you can try again.