Error "File exists" from krb5_init_context

[eichin-krb@thok.org]

A common problem with debugging kerberos errors is that the
com_err/errno value only gives you "what", and you really need "where"
as well... ie. "what were you doing when that broke".  If you're on a
platform with ltrace, I'd suggest trying it, to see what krb5 library
call was in progress (*within* krb5_init_context) when you got that
error; if not, at least try a truss or ktrace and see what syscall
returned EEXIST, and see why it might have failed... 

However, a quick look (with emacs and etags -- rigor would need a real
call graph, and you can do that yourself, probably with a debugger
handy) at krb5_init_context shows it can return, even including
children:

ENOMEM
KRB5_PROG_ETYPE_NOSUPP
KRB5_CRYPTO_INTERNAL
KRB5_CONFIG_CANTOPEN
KRB5_CONFIG_BADFORMAT
any errno from gettimeofday

I don't see any other obvious returns -- most things init does either
can't fail, or the failure is not reported (due to not being important
at that time), or the failure is translated as above...