Mirror of forum.nim-lang.org

12620 :: Compiling with Nim v2.2.0 gives SIGSEGV for yaml loading code

• jasonfi (orginal) [2024-12-08T17:53:48+01:00] view original

  Here's the full output:

  
  nexus/src/nexus/cmd$ nim --path:../.. -d:ssl c programs/nexus.nim
  Hint: used config file '/home/user/.choosenim/toolchains/nim-2.2.0/config/nim.cfg' [Conf]
  Hint: used config file '/home/user/.choosenim/toolchains/nim-2.2.0/config/config.nims' [Conf]
  ......................................................................................................................................................................................................................................................................SIGSEGV: Illegal storage access. (Attempt to read from nil?)
  Run

  I commented code out until I found what was causing this, here's the code it breaks on:

  
      var
        webAppYAML: WebAppYAML
        s = newFileStream(&"{webAppConfPath}/{pathName}.yaml")
      
      load(s, webAppYAML)
      s.close()
  Run

  The load call, specifically, was narrowed down to be the cause of the SIGSEGV.

---

• guzba (orginal) [2024-12-08T22:24:57+01:00] view original

  Is WebAppYAML a ref object? What is load's code?

  A small example is great but it is not so great if it is all private code instead of stdlib or something like that so we can see what is happening.

---

• jasonfi (orginal) [2024-12-09T05:06:26+01:00] view original

  It's an object but it has a field of seq that's a ref object. Making that an object prevents the error.

  Full type code:

  
    Media* = ref object of RootObj
      name*: string
      `type`*: string
      version*: string
      url*: string
    
    
    MediaList* = seq[Media]
    
    
    WebAppYAML* = object
      shortName*: string
      # package*: string
      description*: string
      basePath*: string
      srcPath*: string
      mediaList*: MediaList
  Run

  Thanks for pointing out that ref objects could be the problem! I'll do that as a workaround, but should I file a bug for the compiler? Is this a known issue?

---

• stoking (orginal) [2024-12-09T05:35:27+01:00] view original

  It's probably the load proc from NimYAML.

---