Nvim (v0.2.1-535-g8370373) has started misbehaving on my Red Hat Enterprise Linux 7 box.  It works fine via Putty, but from bash I get an odd character (001b in a litle box; perhaps this is the unicode escape character?) followed by a few other wrong characters when I type : or i (for example).  When I hit escape they go away but they obscure what I'm typing.  This occurs with vim -Nu NONE or vim -Nu NORC.For example, if the first line of text is 1234567890 and I go to the first column and press i it changes to:xx6 q67890(where xx is the 001b character).Vim is fine on the same box.  Nvim used to be fine until I updated it via compiling source.  Reverting back to the previous version doesn't fix it, suggesting it's environmental.  Experimenting a little reveals that this problem goes away if I set the environment variable xterm to nothing.  Usually, though, it's set to xterm-256color so that Nvim's colours are displayed correctly.
Escape character appearing in Neovim when Xterm set to 256-color
neovim