Can't use REGEX in windows powershell

[taliyahpottruff]

If I try to use the command gource --file-filter '(a|b)' for example powershell will respond with:
'b)' is not recognized as an internal or external command, operable program or batch file.

This makes filtering multiple filetypes impossible in Windows Powershell

[chocopoule]

I came accross the same issue and found the following workaround:
set PIPE="|"
gource --file-filter '(a%PIPE%b)'