gdm and gnome-session install confict

[frstan@…]

using MacPorts 1.7.0_rc1 to install gnome (sudo port -d install gnome) I got this error

-->  Activating gnome-session @2.24.1_0
Error: Target org.macports.activate returned: Image error:
/opt/local/share/xsessions/gnome.desktop is being used by the active gdm
port.  Please deactivate this port first, or use the -f flag to force
the activation.
Warning: the following items did not execute (for gnome-session):
org.macports.activate
Error: The following dependencies failed to build: gnome-desktop-suite
gnome-session gnome-system-monitor gtkmm cairomm libsigcxx2 glibmm
pangomm gnome-terminal gnome-user-docs gnome-utils gnopernicus
libgail-gnome libgtkhtml3 seahorse avahi dbus-python25 libdaemon
py25-gdbm gpgme gnupg pth vino yelp firefox-x11 zenity
Error: Status 1 encountered during processing.

I did sudo port -df activate gnome-session and then resumed the install with sudo port -d install gnome was this correct?

I guess whether it will work or not depends on what the gnome.desktop file does. In any case, gdm and/or gnome-session need to be modified so they don't conflict.