SBT Error: "Failed to construct terminal; falling back to unsupported..."

I had the same issue, especially when the TERM environment variable is set to xterm-256color. Setting it to a different value fixed the issue for me, e.g.

export TERM=xterm-color

I found the package which causes this issue: ncurses. I downgraded ncurses to version ncurses-6.0+20170429-1 (I am using Arch Linux) and SBT starts just fine.

Steps for Arch Linux:

cd /var/cache/pacman/pkg
sudo pacman -U ncurses-6.0+20170429-1-x86_64.pkg.tar.xz # or some other older version

Steps for Mac: see https://github.com/jline/jline2/issues/281

I think this issue was introduced with ncurses version 20170506, see: http://invisible-island.net/ncurses/NEWS.html#index-t20170506

+ modify tic/infocmp display of numeric values to use hexadecimal when
      they are "close" to a power of two, making the result more readable.

I filed an issue on the SBT issue tracker: https://github.com/sbt/sbt/issues/3240

Edit: SBT version 0.13.16 includes the fix for this problem.

You can add export TERM=xterm-color to the top of /usr/share/sbt/bin/sbt because $HOME/.sbtconfig is deprecated.