OK cups is working on 4.14 using the following steps with network boot and NFS mounted rootfs
1. added tool-sdk and used tools on the imx8 to do the build, did not use Yocto, local builds instead of cross compiles
1.1 built and installed qpdf-master.zip
2. built and installed poppler-0.76.0.tar.xz, poppler-0.64.0.tar.xz will not work
2.1 poppler install broken, cups-filter will tell you the things to add to /usr/local/include/poppler
3. built and installed pip-master.zip
4. built and installed openjpeg-2.2.0.tar.gz
5. built and installed mupdf-1.14.0-source.tar.xz
6. built and installed libpng-1.6.34.tar.xz
7. built and installed cms2-2.7.tar.gz
8. built and installed hplip-3.18.4.run
9. built and installed ghostscript-9.21.tar.gz
10. cups-filters-1.22.5.tar.xz, will build and install, be careful of install because foomatic-rip conflicts in the install
11. cups-notifier.c and cups-notifier.h need gdbus-codegen, I copied these files from a ubuntu machine,