mdmg seems to get confused when deps have variants on by default

[rogerdpack@…]

Hello. I have this port:

$ port deps rdp-projects
Full Name: rdp-projects @0_6
Fetch Dependencies:   subversion
Library Dependencies: ffmpeg, gocr, ImageMagick, mplayer-edl

If I run, for instance,

$ sudo port mdmg -f rdp-projects

it happily builds and works, and creates a dmg file. So far so good.

If I then re-run that same command, this is what I then get:

$ sudo port mdmg -f rdp-projects
--->  Computing dependencies for rdp-projects
--->  Creating pkg for rdp-projects-0
--->  Package for rdp-projects-0 is up-to-date
...
Error: Requested variants "+gpl2" do not match original selection "".
Please use the same variants again, perform 'port clean ffmpeg' or specify the force option (-f).
Error: org.macports.mpkg for port rdp-projects returned: Processing of port ffmpeg failed
Please see the log file for port rdp-projects for details:
    /opt/rdp_project_local/var/macports/logs/_Users_rogerdpack_dev_mplayer-svn_mplayer_patches_port_dir_multimedia_rdp-projects/rdp-projects/main.log
To report a bug, follow the instructions in the guide:
    http://guide.macports.org/#project.tickets
Error: Processing of port rdp-projects failed

(as a note, specifying -f for force apparently does nothing to help here)

$ port clean ffmpeg does "temporarily" overcome the problem, so that it works again once, but then some other dependency will fail in like manner, like perl5. So if I then run a "port clean perl" and try it again, ffmpeg now fails again, since it's "unclean" from the previous run. So I have to manually, one after another figure out all the dependencies, and clean them all (or clean all installed) first.

Anyway appears this has been seen before: ​https://lists.macosforge.org/pipermail/macports-users/2009-December/018201.html though I didn't see a resolution.

Anyway, see if you can reproduce it.
Thanks!
-roger-