export SANE_DEBUG_RTS8891=255 export SANE_DEBUG_RTS8891_LOW=255 export SANE_DEBUG_RTS88XX_LIB=255 export LD_PRELOAD=backend/.libs/libsane-rts8891.so export SANE_CONFIG_DIR=backend frontend/.libs/scanimage -d rts8891 2>rts8891-scan.log >rts8891-scan.pnm