That is a strange error; I do not know what would
cause
it. Try without
the -j4 flag (i.e. a single-core build) and see what
happens.
Okay. Looks like another single processor compile. I removed the libcaldav package and the
-j4 flag.
The package built. So the only remaining test for this package is to compile with and
without libcarddav.
Whew!