Building using VS 2015 - billdinger/Win32-OpenSSH GitHub Wiki
Building using Visual Studio 2015
Download and Install VS 2015 Community Edition
Clone https://github.com/PowerShell/openssh-portable
Download the latest PowerShell LibreSSL release and copy LibreSSL folder to $openssh-portable\contrib\win32\openssh.
Open "contrib\win32\openssh\Win32-OpenSSH.sln" in Visual Studio and continue building Win32-OpenSSH binaries
If you see crt headers related errors on recompilations, try deleting the following file, and do a clean build subsequently
contrib\win32\win32compat\inc\crtheaders.h