Naofumi Yasufuku <naofumi@yasufuku.dev> writes:
[,,snip..]
> +          MAC_LIBS="-L$(dirname $($BREW ls -v libgccjit | \
> +                                  grep -E 'current/libgccjit\.(so|dylib)$' | \
> +                                  head -1))"
> +          if test "${MAC_LIBS}" = "-L"; then
> +            # Try for Homebrew libgccjit < 12.1.0.
> +            MAC_LIBS="-L$(dirname $($BREW ls -v libgccjit | \
> +                                    grep -E 'libgccjit\.(so|dylib)$' | \
> +                                    head -1))"

"x" is added for "${MAC_LIBS}" test, just in case.  Revised patch is
attached.  I also attach emacs-28 config.log's against both
homebrew libgccjit-12.1.0 and libgccjit-11.3.0.