sanity-config issue

[Andriy Gapon]

In some ports I am getting an error message about how make doesn't know how to
make sanity-config after exiting from config menu.
I see that there is
	@${MAKE} sanity-config
line at the end of the config target script.

I use WRKDIRPREFIX=/usr/obj and I noticed that e.g. in the case of
mail/thunderbird port the make command was being run from
/usr/obj/usr/ports/mail/thunderbird.

My workaround was to prepend "cd ${.CURDIR};" before the make command.
I see that this is a popular theme in bsd.port.mk, but I am not sure why it is
needed and if my workaround is actually correct.

Hope that this is useful.

-- 
Andriy Gapon