A few minutes back I filed a feedback assistant issue for this (FB18173706), but I am not sure I filed it in the correct category and I can't find a way to edit it either. So posting this message here just to have to assigned in the right category if appropriate. The issue is as follows.
On macOS 26 Tahoe Beta, "man sw_vers" has this among other details:
Previous versions of sw_vers respected the SYSTEM_VERSION_COMPAT environment variable to provide compatibility fallback versions for scripts which did not support the macOS 11.0+ version transition. This is no longer supported, versions returned by sw_vers will always reflect the real system version.
It says that SYSTEM_VERSION_COMPAT is no longer supported. That doesn't look right, because running sw_vers as follows on macOS 26 Beta results in:
SYSTEM_VERSION_COMPAT=1 sw_vers
ProductName: macOS
ProductVersion: 16.0
BuildVersion: 25A5279m
i.e. setting the environment variable SYSTEM_VERSION_COMPAT=1 results in sw_vers reporting the version as 16.0. Now try with SYSTEM_VERSION_COMPAT=0, and the result is:
SYSTEM_VERSION_COMPAT=0 sw_vers
ProductName: macOS
ProductVersion: 26.0
BuildVersion: 25A5279m
notice the output says 26.0. So it appears that SYSTEM_VERSION_COMPAT is supported even on macOS 26. I think the man page requires an update to match this behaviour.
