MacPorts installs libraries I already have?

[Scott Heftler]

Hello.

I MacPorted a bunch of stuff yesterday (libpng, netpbm, and gocr), and
MacPorts added repeats of lib files, man pages, and other stuff I
ALREADY HAD in both my system-installed libraries and in
/usr/local/share!  What’s up with that?

For example, when I MacPorted gocr, it fetched and installed jpeg 6b_3
-- but I already have it.

Then it installed jasper 1.900.1_1+darwin_9.  Already have that, too.

Then it installed tiff.  Already have that, too.

Then it installed netpbm, which I had already installed myself --
using the ordinary ./config, make, install -- into /usr/local/share.

Two questions:

(1) Shouldn’t MacPorts LOOK to see if I have what it thinks it should
install?  Is there a way to MAKE MacPorts look first, and thus skip
duplicate files?

(2) Should I now delete ONE of the duplicate file-sets?  If so, which
should I kill -- the ordinary /usr/...  embedded set, or MacPorts'
/opt/... embedded set?

Thank you so much!