If you download the git manually you do not have a git-environment and cannot perform a git pull. Do a git clone, not a download.
My mistake: if the preparation fails there are indeed no enigma2* files in ./deps. Better to be sure though.
As explained before I do not have a UFS910. Receivers I do not posses I cannot test; the flash-environment was carefully copied from Max but apparently contains some mistakes.
Recent changes in the build environment caused a failure in kernel version detection. This has been fixed. The error when starting mksquashfs4.0 has been fixed as well. Do a git pull in the flash directory. Currently there is (and was) no support for Neutrino on USB for UFS910 flash. This was not detected, but now displays a message.
Regards,
Audioniek.