https://bugzilla.redhat.com/show_bug.cgi?id=1087697
--- Comment #9 from Matthew Heon mheon@redhat.com --- Pull request sent to upstream for this (https://github.com/dotcloud/docker/pull/6955). Solution has some quirks (SIGTTIN, SIGTTOU, SIGTSTP are not proxied, for example), but does enable signal proxying with TTY mode specified.