Go downloads for czniz modules seem to broken

Started happening in the last few hours, both on our build server and locally. Not sure where they've gone?

go: finding modernc.org/golex v1.0.0
go: finding modernc.org/cc v1.0.0
go: finding modernc.org/mathutil v1.0.0
go: finding modernc.org/strutil v1.0.0
go: finding modernc.org/xc v1.0.0
go: modernc.org/golex@v1.0.0: unknown revision v1.0.0
go: modernc.org/mathutil@v1.0.0: unknown revision v1.0.0
go: modernc.org/xc@v1.0.0: unknown revision v1.0.0
go: modernc.org/cc@v1.0.0: unknown revision v1.0.0

cheers

Scott