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5669 :: What do you do when the compiler crashes?

• spip (orginal) [2019-12-11T03:23:16+01:00] view original

  What can be done to find what makes the Nim compiler crash? I've been translating a Python program to Nim and the compiler crashes with the error

  
  fatal.nim(39)            sysFatal
  Error: unhandled exception: 'sym' is not accessible using discriminant 'kind' of type 'TNode' [FieldError]
  Run

  I've built a debugging version of nim and I get the same stack trace as reported in this issue. I've tried to reduce the scope of the compilation to limited sections of the source without being able to find where the problem lies, probably a syntax error like in the issue but I can't spot it.

  Here is the code https://play.nim-lang.org/#ix=246h

  Any hint welcome.

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• spip (orginal) [2019-12-11T03:33:13+01:00] view original

  I just saw that the code in the playground is not the last version of the source that is on another PC that I can't access presently, where there are syntax errors like at line 91

  # The set of constraints which are currently unsatisfied.
    unsatisfied = HashSet[T].toHashSet(keys(choices))
  Run

  and probably other I already corrected. But the bug in the Nim compiler is still present. I'll try to update the source with the latest version tomorrow.

  My question is both where is the problem with the compiler in that source and more importantly, how to find it when such situation occurs.

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• spip (orginal) [2019-12-12T01:54:52+01:00] view original

  For others encountering a similar situation, when commenting out portions of code does not help or running a nim compiler with debugging symbols does not help either, here is what I've done.

  1. Searching in Nim issues shows that the compiler has become more sensitive to syntax errors lastly.
  2. From that, I decided to run it with different versions of the compiler, and using the Playground does not require you to install many old versions on your computer. I found that version 0.19.6 reported exactly the symbol where the compiler was choking. Correcting it, I was able to switch back to version 1.0.4 and continue correcting the remaining syntax errors.

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• Arrrrrrrrr (orginal) [2019-12-13T17:04:54+01:00] view original

  What I do is to compile using --verbosity:3 https://nim-lang.org/docs/nimc.html#compiler-usage-verbosity-levels

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• spip (orginal) [2019-12-15T00:33:19+01:00] view original

  What I do is to compile using --verbosity:3

  In that particular case, it did no difference, even with the debug compiler...

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