FMU library - seg fault

[mantielero]

I've been off programming Nim for a while. Now I was revisiting and old project 
and I am hitting a failure I don't know how to address.

I am creating a library in Linux: `inc.so` which complies with the FMU standard 
(I was doing this about 2 years ago).

The code compiles fine, but when I pass the library through the FMU checker I 
get the following error:
    
    
    [...]
    0x7fc4aed10060"(r: ..., i: ..., b: ..., s: ..., isPositive: ..., time: 0.0, 
instanceName: Test FMI 2.0 ME, type: fmi2ModelExchange, GUID: 
{8c4e810f-3df3-4a00-8276-176fa3c9f008}, functions: ..., loggingOn: 1, 
logCategories: [1, 1, 1, 1], componentEnvironment: ..., state: 
modelInstantiated, eventInfo: (newDiscreteStatesNeeded: 0, terminateSimulation: 
0, nominalsOfContinuousStatesChanged: 0, valuesOfContinuousStatesChanged: 0, 
nextEventTimeDefined: 0, nextEventTime: 0.0), isDirtyValues: 1, 
isNewEventIteration: 0)"
    Traceback (most recent call last)
    /home/jose/src/nimlang/fmu/ex02_moving_to_nim/lib/functions/others.nim(203) 
fmi2Instantiate
    /home/jose/.choosenim/toolchains/nim-1.6.10/lib/system/assign.nim(143) 
genericAssign
    /home/jose/.choosenim/toolchains/nim-1.6.10/lib/system/assign.nim(132) 
genericAssignAux
    /home/jose/.choosenim/toolchains/nim-1.6.10/lib/system/assign.nim(25) 
genericAssignAux
    /home/jose/.choosenim/toolchains/nim-1.6.10/lib/system/assign.nim(22) 
genericAssignAux
    /home/jose/.choosenim/toolchains/nim-1.6.10/lib/system/assign.nim(140) 
genericAssignAux
    SIGSEGV: Illegal storage access. (Attempt to read from nil?)
    ./build.sh: line 8: 569360 Segmentation fault      (core dumped) 
./fmuCheck.linux64 inc.fmu
    
    
    Run

The file `others.nim` simply instantiate an object:
    
    
    {.push exportc:"$1",dynlib,cdecl.}
    
    proc fmi2Instantiate*( instanceName: fmi2String;
                           fmuType: fmi2Type;
                           fmuGUID: fmi2String;
                           fmuResourceLocation: fmi2String;
                           functions: fmi2CallbackFunctions;
                           visible: fmi2Boolean;
                           loggingOn: fmi2Boolean): ModelInstance =
        ....
        var comp:ModelInstance
        comp.time = 0
        comp.instanceName = instanceName
        ...
        echo repr $comp
        return comp    #<--- THIS IS THE LINE FAILING
    
    
    Run

Any clue about in which direction I should look-at?