Potential deadlock when using piece "Dummy" with promotion

[jvarnholt]

I found a stipulation with a potential issue in Popeye 4.89.

On my Windows-PC there is no printed output after more than one day runtime. Maybe caused by an internal endless loop or similar.
Problem seems to be the bPf2 (promotion option) because with using rook or bishop there is no issue.

The stipulation is:
anfangproblem
autor Potential Bug in Popeye 4.89
forderung 14->ser-=1
steine weiss la1 ka4 dd8 due1 duf6
schwarz duc1 dud2 due3 due8 bf2 bf7 kf8 dug5 lh6 sh7
opt zugnummern
endeproblem

Please check if this deadlock is reproducible and investigate.