Julia version 1.6.4, the fourth patch release in the 1.6 series of releases, is now available. You can get binaries for glibc Linux (i686, x86-64, AArch64, ARMv7), musl Linux (x86-64), FreeBSD (x86-64), macOS (x86-64), and Windows (32-, 64-bit) at https://julialang.org/downloads.
As a patch release, 1.6.4 contains no new features or breaking changes, only bug fixes, documentation improvements, and performance improvements. You can see the list of commits included since 1.6.3 here. We recommend anyone currently using 1.6 versions upgrade to 1.6.4.
Under which circumstances do you observe this? I’m on macOS as well and for me adding a github repo works just fine in 1.6.* (can’t try yours because it seems to be private).
(Sorry, I guess that should go into the issue on github when it exists.)