[metapost] mpost option -s internal="string"

[Nicola]

Hi,
when I use (1.209):

mpost -s outputtemplate="foo.eps" -s outputformat="svg" foo.mp

I get

Warning: outputformat=0: value has the wrong type, assignment ignored.
Warning: outputtemplate=0: value has the wrong type, assignment ignored.

What's wrong?

Nicola