bsd.port.mk FETCH_ARGS defaults, why "-A" ?

[John Marino]

For months I've been getting a lot of fetch failures in ports that I
couldn't reproduce outside of them.  It appears it is caused by the
default "-A" passed to fetch.

For example, /usr/ports/emulators/javatari will fail with "make fetch"
but it will succeed with with "make fetch FETCH_ARGS=-Fpr"

I'd like to understand why "-A" is the default.  Clearly many distfiles
could be retrieved that aren't, so I'd like to know what -A is saving us
from, and why that would be worse than the current situation?

Thanks,
John