export LIBRARY_PATH=/local/qt/lib/dir. Then run configure/make.
Save the following as a shell script called aarch64-linux-gnu-g++:#!/bin/sh exec /real/path/to/aarch64-linux-gnu-g++ -L/local/qt/lib/dir "$@"
Then 'chmod +x' the script and put it first in your PATH.
I will try these as well as the LDFLAGS/CXXFLAGS options the next time I try a build, and update this thread if one of them works.