invalid syntax error for display_opts - {"pop","source"}

[BKhalili]

Hi,

I have installed locuszoom on our server and when I try to run: locuszoom -h
I get the following syntax error. Can you help me resolve it please?
FIle"/PATH/locuszoom/bin/../src/m2zfast.py", line 1122
display_opts = display_opts - {"pop","source"}
^
SyntaxError: invalid syntax