Nim “free(): invalid pointer” segfault (dynlib)

[Nlits]

Error: (with `import segfaults`)
    
    
    free(): invalid pointer
    Traceback (most recent call last)
    /home/runner/libmtg/src/libmtg/cards.nim(119) test1
    SIGABRT: Abnormal termination.
    Aborted (core dumped)
    Error: execution of an external program failed: 
'/home/runner/libmtg/tests/test1'
           Tip: 5 messages have been suppressed, use --verbose to show them.
    tools.nim(36)            doCmd
        
        Error:  Execution failed with exit code 1
            ... Command: /home/runner/libmtg/nimble-env/bin/nim c 
--noNimblePath -d:NimblePkgVersion=0.1.0 --hints:off -r --path:. 
/home/runner/libmtg/tests/test1
    
    
    Run

Things to note: The trace back line num is wrong, idk why but segfaults usually 
get it wrong. How do I fix this?

Nim code:
    
    
    proc load*(cs: var CardSet) =
      let lib = TrackedLibHandle(loadLib(cs.sourcePath))
      cs.lib = lib
      
      block:
        let loadProc = cast[CardSetLoadProc](lib.checkedSymAddr("load"))
        let cards = loadProc()
        for key, value in cards:
          cs.cards[key] = Card()
          
          var vvalue = value
          vvalue.source = addr cs
          echo vvalue.eventHandle
          if vvalue.eventHandle != "":
            let name = cstring(vvalue.eventHandle)
            let prc = block:
              echo 0
              let p = lib.checkedSymAddr(name) # Error
              echo 1
              cast[EventHandleProc](p)
            
            echo "Inbetween"
            vvalue.eventHandleProc = prc
          
          if vvalue.statelessEventHandle != "":
            let name = cstring(vvalue.statelessEventHandle)
            let prc = cast[EventHandleProc](lib.checkedSymAddr(name))
            vvalue.statelessEventHandleProc = prc
          
          
          cs.cards[key][] = vvalue # Assign ref
    
    
    Run