A difficult-to-reproduce segmentation fault.

[Stevengre]

The image shows an error we encountered during the development of our project. This error may also occur when running krun --depth 0. We suspect it is caused by an anomaly in the automatic filling of cells.

Initially, we provided a program similar to the one below:

module TEST-SYNTAX
imports INT-SYNTAX
syntax Top ::= List{Inst, ";"}
syntax Inst ::= "spawn" Int
endmodule

module TEST
imports TEST-SYNTAX
imports INT

configuration
<pgm> $PGM:Top </pgm>
<ks>
 <k-thread multiplicity="*" type="Map">
  <kid> 0 </kid>
  <k> 0 </k>
 </k-thread>
</ks>

rule 
<pgm> spawn X ; T:Top => T </pgm>
(.Bag =>
<k-thread>
  <kid> !_:Int </kid>
  <k> X </k>
</k-thread>
)

rule 
<k> X => X +Int Y </k>
<k-thread>
  <k> Y => Y -Int Y </k>
  ...
</k-thread>
requires Y >Int 0

endmodule

After placing <k> into the </k-thread>, the bug disappears. However, this program itself can be correctly compiled using kompile and executed with krun. Therefore, we have not yet identified the minimal reproducible example. Additionally, due to the complexity of our project and the lack of backups for the error, we are currently unsure how to reproduce the issue.