Hi Martin, the stack should probably be an even hex number, in this case 64k equals 65536 or 0x10000H.
There's other ways to set the stack size such as the -Zstack option, -Zstack 0x2000 gives 8MB stack. I usually just go with the default, which is pretty big now a days, though I can't remember how big. In the EMX days it was on the small side.
Generally executables don't need a def file, though they are handy for adding bldlevel info and in the case of a PM app like this, the WINDOWAPI forces it to be a PM app rather then cmd line. It is possible to morph into a PM app as well, you end up with a console window along the PM window.
I think a lot of this def file is from the 16 bit days and can be simplified to,
; WALKER defintion file
NAME WALKER WIDOWAPI
DESCRIPTION 'Walker utility (C) Lee S. Fields, 1989'
or better, something like,
; WALKER defintion file
NAME WALKER WINDOWAPI
DESCRIPTION '@#OS2World:4.00#@##1## 31 Mar 2022 21:17:32 ARCAOS-444::::::v4.0@@Moving icon test program'
Which gives,
H:\tmp\PMwalker>bldlevel walker.exe
Build Level Display Facility Version 6.12.675 Sep 25 2001
(C) Copyright IBM Corporation 1993-2001
Signature: @#OS2World:4.00#@##1## 31 Mar 2022 21:17:32 ARCAOS-444::::::v4.0@@Moving icon test program
Vendor: OS2World
Revision: 4.00
Date/Time: 31 Mar 2022 21:17:32
Build Machine: ARCAOS-444
FixPak Version: v4.0
File Version: 4.0
Description: Moving icon test program