If I understand https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=384593,
this functionality was disabled by default on Debian-based systems for
security reasons.

Philipp Stephani <p.stephani2@gmail.com> schrieb am Fr., 17. Apr. 2015 um
08:25 Uhr:

> Maybe something needs to be enabled? The documentation says "These
> controls may be disabled using the allowWindowOps resource." I'll try it
> today.
>
> Stefan Monnier <monnier@iro.umontreal.ca> schrieb am Fr., 17. Apr. 2015
> um 04:40 Uhr:
>
>> Is that normal?  Do you guys see the same?  I'm using Debian's "xterm"
>> package version 312-2, for what it's worth.
>>
>>
>>         Stefan
>>
>>
>> >>>>> "Stefan" == Stefan Monnier <monnier@IRO.UMontreal.CA> writes:
>>
>> >>> Yes, I took a look and I'll work on integrating the paste
>> functionality.
>> >>> Since cut and paste are mostly independent of each other, maybe you
>> could
>> >>> already integrate the cut patch?
>> >> I just installed it (after adding a ChangeLog, and although it still
>> >> lacks an etc/NEWS entry).
>>
>> > BTW, I can't seem to make this feature work for me.  I do:
>>
>> >    emacs -Q -nw
>> >    M-x trace-function RET xterm--set-selection RET
>> >    C-SPC M-f M-f M-f M-w
>> >    <go to a previously running Emacs session in GUI mode>
>> >    C-y
>>
>> > and instead of getting the three words from *scratch*, I get whatever
>> > was already there before in the clipboard.  Yet, the trace buffer shows
>> > that xterm--set-selection was called alright (and edebugging it also
>> > indicates that it seems to be doing what it should).
>>
>>
>> >         Stefan
>>
>