tests/parallel/tflowvar.nim failure on OpenBSD

[euantorano]

The test tests/parallel/tflowvar.nim is failing on the OpenBSD CI:

Category: parallel
Name: tests/parallel/tflowvar.nim C
Action: run
Result: reExitcodesDiffer
-------- Expected -------
exitcode: 0
--------- Given  --------
exitcode: 1

Output:
foobarfoobar
bazbearbazbear

tflowvar(45102) in free(): use after free 0xb1447ac3740
Traceback (most recent call last)
tflowvar.nim(36)         tflowvar
tflowvar.nim(31)         p
SIGABRT: Abnormal termination.