[NTG-context] "Darwin x86_64" is not supported yet error.

Dear all, Today I tried to update ConTeXt using first setup and got an error message: Error: your system "Darwin x86_64" is not supported yet. "first setup" worked well before I upgrade Mac OS to Mountain Lion from snow leopard two weeks ago. The current ConTeXt version and Luatex version in my Mac are ConTeXt ver: 2012.07.20 00:58 MKIV fmt: 2012.7.20 int: english/english system > cont-new.mkiv loaded … mkiv lua stats > latex banner - this is latex, version beta-0.70.2-2012052309 (tex live 2012) How to update the ConTeXt to latest beta? Thank you. Best regards, Dalyoung