roel@roel:/tmp$ rpmbuild -tb iscan_2.29.3-1.tar.gz
warning: line 70: prereq is deprecated: PreReq:  sane-backends
error: Failed build dependencies:
 libusb >= 0.1.6 is needed by iscan-2.29.3-1.usb0.1.ltdl7.x86_64
 libxml2-devel is needed by iscan-2.29.3-1.usb0.1.ltdl7.x86_64
 gtk2-devel is needed by iscan-2.29.3-1.usb0.1.ltdl7.x86_64
 libpng-devel is needed by iscan-2.29.3-1.usb0.1.ltdl7.x86_64
 libjpeg-devel is needed by iscan-2.29.3-1.usb0.1.ltdl7.x86_64
 libtiff-devel is needed by iscan-2.29.3-1.usb0.1.ltdl7.x86_64
 libtool-ltdl-devel is needed by iscan-2.29.3-1.usb0.1.ltdl7.x86_64
 gimp-devel is needed by iscan-2.29.3-1.usb0.1.ltdl7.x86_64
 sane-backends-devel is needed by iscan-2.29.3-1.usb0.1.ltdl7.x86_64