Investigating PUP-2169 i've discovered that the Selinux.matchpathcon function is marked as deprecated.
man 3 matchpathcon
This family of functions is deprecated. For new code, please use selabel_open(3) with the SELABEL_CTX_FILE backend in place of matchpath‐con_init(), use selabel_close(3) in place of matchpathcon_fini(), and use selabel_lookup(3) in place of matchpathcon().