After upgrading to XCode 8 and MacOS to 10.12.2, I was getting a linker error when linking with macport's GCC 6: "ld: unexpected token: !tapi-tbd-v2", so this script creates a lybrary symlink for every .tbd file in a given MacOSX SDK path, so that the linker doesn't need the .tbd file at all.

mac_fix_tbd_libraries.sh

#!/bin/bash

if [ $# -eq 0 ]; then
	echo "Usage: $0 MACOSX_SDK_PATH"
	echo "Example: $0 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk"
	exit 1
fi


for tbd in $(find -L "$1" -name '*.tbd'); do
	dylib="$(cat $tbd | grep '^install-name:' | sed 's/^install-name:[[:space:]]*\(.*\)/\1/')"
	dylib_symlink="$(dirname $tbd)/$(basename $dylib)"
	if [ -e "$dylib_symlink" ]; then
		echo "DYLIB exists: $dylib_symlink"
		if [ ! -z "$(file "$dylib_symlink" | grep 'Mach-O.*library')" ]; then
			echo "  IS DYLIB"
		else
			echo "  NOT DYLIB"
		fi
	else
		ln -s "$dylib" "$(dirname $tbd)/"
		echo "Creating symlink $dylib_symlink"
	fi
done