I found the following code in u-boot.inc

if not d.getVar("UBOOT_MACHINE", True):
     PN = d.getVar("PN", True)
     FILE = os.path.basename(d.getVar("FILE", True))
     bb.debug(1, "To build %s, see %s for instructions on \
                     setting up your machine config" % (PN, FILE))
     raise bb.parse.SkipPackage("because UBOOT_MACHINE is not set")

and while I don't have UBOOT_MACHINE set, u-boot still follows with no 
problems through do_fetch, do_configure, do_compile and so on, and 
finishes without any problem/error. I would have expected to be skipped 
as the above code snipped would imply, but I cannot find that log 
message anywhere (nor any error to indicate failure). Can somebody point 
me in the right direction with this?

Radu