macOS 26 Beta - man page of sw_vers is not accurate

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Created Jun ’25

Replies 5

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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.

Answered by darkpaw in 844428022

Just add a comment to the original feedback report. Posting updates to the Developer Forums won't really go anywhere.

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Answer 1

darkpaw OP

Jun ’25

Accepted Answer

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Just add a comment to the original feedback report. Posting updates to the Developer Forums won't really go anywhere.

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Answer 2

DTS Engineer OP

Apple

Jun ’25

I filed a feedback assistant issue for this FB18173706

Thanks for that.

Just add a comment to the original feedback report.

Yep. That’s definitely the right way forward here.

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Answer 3

jaikiran OP

Jun ’25

Thank you both for the help. I've added a comment to the feedback issue requesting to have it placed in the correct category.

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Answer 4

Sylican OP

Jun ’25

kinda ok

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Answer 5

jaikiran OP

2w

An update on this one - Apple replied to the FB18173706 issue that I had filed and they noted that the issue has been resolved starting Beta3 of macos 26.

As part of the fix, the man page of sw_vers continues to remain the same as it was previously but the support for the environment value SYSTEM_VERSION_COMPAT is no longer present in macos 26. i.e. irrespective of what value you set to SYSTEM_VERSION_COMPAT or even if that environment variable is unset, the macos version reported by sw_vers will always be 26. So this behaviour now matches what's noted in the man page for sw_vers.

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