any way to track "SIGSEGV: Illegal storage access"?

[retsyo]

One of my old project use wnim for gui, winim for using .NET DLLS. And the compiled command-line is

nim c -d:release --opt:size -d:quick --opt:size --passL:-s --passc:-flto   -r myapp.nim

• when I close the myapp20220922.exe file, which is compiled on September 22nd, 2022, everything seems ok
• but now, I updated to latest nim(Nim Compiler Version 2.1.1 [Windows: amd64], Compiled at 2023-11-12), winim(winim-3.9.2-154c271e1d766fca5aea32beecec5645e6d2e114) and wnim(wnim-0.13.3-eba76f28624eb4c74bdda19830fae74d4dbc1ee2), when I close new built myapp20231112.exe, I get

SIGSEGV: Illegal storage access. (Attempt to read from nil?)
Error: execution of an external program failed: 'D:\tmp\compareexcel\myapp20231112.exe'

Any way to track which line of the code produces this? Thanks

[retsyo]

yet another question, for the same source code, myapp20231112.exe is 7.67k, while myapp20220922.exe is 4.17k. What causes such a bigger bloat in size? Thanks

[retsyo]

ringabout gave a solution
use --mm:refc

memory management mode	work or not
orc	SIGSEGV: Illegal storage access. (Attempt to read from nil?)
arc	yes
refc	yes
markAndSweep	yes
Boehm	SIGSEGV: Illegal storage access. (Attempt to read from nil?)
go	I have not found libgo.dll to run exe
none	yes