Dynlib passing value back to main app causes SIGSEGV error

[gcao]

Hi,

With below code I'm getting a strange error with no stack trace. Any 
suggestions?

app.nim 
    
    
    import dynlib
    
    type
      Value* = ref object
      
      P* = proc(): Value {.nimcall.}
    
    when isMainModule:
      var lib = loadLib("libext.dylib")
      var test: P = cast[P](lib.symAddr("test"))
      echo test() != nil
    
    
    Run

ext.nim 
    
    
    import ./app
    
    proc test*(): Value {.dynlib exportc.} =
      Value()
    
    
    Run
    
    
    $ nim -v
    Nim Compiler Version 1.4.6 [MacOSX: amd64]
    Compiled at 2021-05-22
    Copyright (c) 2006-2020 by Andreas Rumpf
    
    active boot switches: -d:release
    
    $ nim c --app:lib --outdir:. ext.nim
    
    $ nim c -r app.nim
    CC: stdlib_system.nim
    CC: app.nim
    Hint: /Users/gcao/proj/gene/tmp/bin/app  [Exec]
    true
    No stack traceback available
    SIGSEGV: Illegal storage access. (Attempt to read from nil?)
    Error: execution of an external program failed: 
'/Users/gcao/proj/gene/tmp/bin/app '
    
    
    Run