Since the Android folks decided that MTP should be the way to connect Android devices via USB I ran into some trouble while trying to get comfortable access to the OnePlus One. There are a couple of forum threads and blog entries out there how to hack some udev rules and use scripts that try to automount the MTPFS. Some recommend mtpfs others use go-mtpfs or jmtpfs. I've tried them all and the result was still not what I wanted to have. Why can't I just plug it in and have it pop up in thunar, like any other USB/Flash device?

Well, the answer is simple: Because I have forgotten to supply the mtp USE flag for gvfs, which manages all mounting related tasks in Xfce4 for me. I also switched to libmtp-9999, because the stable release doesn't know the OnePlus One yet.

Since it's basically a per machine decision, whether it's probable, that it will ever have to mount an MTP device, just put mtp into your global USE flags in /etc/portage/make.conf

Let's see how that would play out:

$ emerge -upvND --with-bdeps=y @world

And voila:

[ebuild     U *] media-libs/libmtp-1.1.8 [1.1.6-r1] USE="crypt -doc -examples -static-libs" 0 kB
[ebuild   R    ] gnome-base/gvfs-1.20.2  USE="cdda gtk http mtp* udev udisks -afp -archive -avahi -bluray -fuse -gnome-online-accounts -gphoto2 -ios -libsecret -samba -systemd {-test}" 0 kB

After the emerge and logout/login to get gvfs reloaded you're good to go.

Connected to a Thinkpad x230 USB 2.0 port it sustained about 29MB/s read transfer rate (copying OnePlus One 4k videos to the Thinkpad's SSD), which is more or less the maximum one can get out of USB 2.0 anyways.