It works now, I have no idea what changed. But it's safe to say, it must be something...
I tried to eliminate other variables so I attempted the build with clang37, clang38,...
Just to clarify that happens in the MCS51 device lib.
mcs51 device/lib does not build with boost 1.63.0
Remove broken reference to bsdadminscripts.1
Port buildflags from original bsdadminscripts
Update data directory
Added tag 1.5.1 for changeset c6f1a961d9ba