I’ve been trying to backup an FP1 with adb. The backup finishes in a few seconds without any error but creates a file only a few bytes. The same thing is described at Adb backup, starts but doesn’t save anything
I tried with some older releases of adb from the fedora build system ( https://koji.fedoraproject.org/koji/packageinfo?packageID=12895 ). The last good one is
android-tools-20141219git8393e50-5.fc24.x86_64.rpm . It ran fine on Fedora 28, so I’d guess it would work on other RPM based linux distros.
wget https://kojipkgs.fedoraproject.org//packages/android-tools/20141219git8393e50/5.fc24/x86_64/android-tools-20141219git8393e50-5.fc24.x86_64.rpm sudo dnf install android-tools-20141219git8393e50-5.fc24.x86_64.rpm