Perhaps useful information for those who program, but irrelevant for
this thread, since WAV files > 2GiB don't require 64bit at all.

libsndfile on Arch, this is what the OP does use, is configured with
"--prefix=/usr --disable-sqlite" and it's the latest official upstream
release without patches and no changes excepted of 

  sed -i 's|#!/usr/bin/python|#!/usr/bin/python2|' src/binheader_writef_check.py \
    src/create_symbols_file.py programs/test-sndfile-metadata-set.py
  sed -i 's|python|&2|' src/Makefile.am