Hello, Due to recent changes in mcuboot git (use of submodules) you may hit issues with newt upgrade|install|sync commands. There is a short term hotfix merged into newt master to workaround this.
Since this is also affecting new users we may need to release newt 1.7.1 (only newt tool) in next few days to address this issue. -- pozdrawiam Szymon Janc
