libx11-xcb1 2:1.6.3-1ubuntu2.2 (s390x binary) in ubuntu xenial

 libX11-xcb provides functions needed by clients which take advantage of
 Xlib/XCB to mix calls to both Xlib and XCB over the same X connection.
 .
 More information about X.Org can be found at:
 <URL:http://www.X.org>
 .
 More information about XCB can be found at:
 <URL:http://xcb.freedesktop.org>
 .
 This module can be found at
 git://anongit.freedesktop.org/git/xorg/lib/libX11