Hi,

When I use 2017.12.09 version git emacs. Tramp works correctly: it promotes
to ask me the passwork.
When I use 2017.12.17 version (or after) git emacs, Tramp can't ask me
password and hangs at waiting for feedback from remote.

I look into the trace and debug buffer, and found that it send command
"exec plink -l". However, "exec" is not an internal nor external command in
CMD in windows, and then stopped.
The trace and debug files can be found at:
https://github.com/ShuguangSun/emacs-tramp-exec-bug-20171223


Best Regards,
Shuguang