FFMPEG_DIR is relative and portable; OCIO_INSTALL_DIR=/usr is this machine's system-OCIO preference (CI overrides it via GITHUB_ENV; delete that line to use the vendored static OCIO build elsewhere).
FFMPEG_DIR is relative and portable; OCIO_INSTALL_DIR=/usr is this machine's system-OCIO preference (CI overrides it via GITHUB_ENV; delete that line to use the vendored static OCIO build elsewhere).