----- Solution ----
When I startup the host system, which is frugal install of LFS 6.3 LiveCD, it always asks me to choose my locale. I had been choosing 'English,US (ISO-8859-1)', but the aforementioned glibc test would not complete, and outputed the errors above.
But if I choose 'Default/other' instead as the locale for the host system, then the glibc test runs to completion, with only the annexc.out error, which is ignored.
So there it is, problem solved. Altho I'm not sure why.