Yes, it is specified to macOS.

I belive that it is specified to update of xcode that was somewhere at the end of December.

-- 
wbr, Kirill

On 14. Jan 2021, at 04:32, Eli Zaretskii <eliz@gnu.org> wrote:

Date: Thu, 14 Jan 2021 03:19:15 +0100
Cc: 45817@debbugs.gnu.org
From: "Kirill A. Korinsky" via "Bug reports for GNU Emacs,
the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>

I'd like to confirm that it isn't a emacs bug.

After reinstall from sources gcc10 an issue disappeared.

Link to mackport related issue: https://trac.macports.org/ticket/61896

Is this specific to macOS?

In any case, if it's known that specific versions of GCC cause
problems on specific platforms, we should reject those versions (for
the libgccjit usage purposes) in configure, I think.