I used to be able to be able to do the following to copy text from xterm in Fedora and Debian VMs:
1. Select/highlight the desired text, thereby inserting it into the PRIMARY buffer.
2. Press <Ctrl + middle mouse button> in order to bring up a menu (I think it was the "VT Options" menu).
3. In this menu, select the option to copy text from the PRIMARY buffer to that VM's local clipboard.
4. Press <Ctrl + Shift + C> to copy text to the Qubes inter-VM clipboard and proceed as usual.
However, some time ago, step 2 suddenly stopped working, and I have no idea why. Pressing <Ctrl + middle mouse button> in xterm now does nothing, as far as I can tell. I've checked my trackpad/mouse settings, and everything seems fine and unchanged. I've tried pressing the left and right mouse buttons simultaneously instead, but nothing.
I know that I can probably create custom xterm settings that will allow me to copy text, but I'd still like to know whether there's a way to do it by default for cases in which the VM is uncustomized. Does anyone know if there is such a way?