Re: cygwin git and golang: how @{u} is handled

>I am experiencing a strange behavior and I'm not certain if it is a
> problem with golang or the cygwin version of git.
>
> Steps to reproduce:
> Use golang's os/exec library to execute
> exec.Command(os.Args[1],"log","@{u}") // where os.Args[1] is either
> cygwin git or Windows git
>
> Expected result:
> commit 09357db3a29909c3498143b0d06989e00f5e2442
> Author: John Cheng <johnlicheng@gmail.com>
> Date:   Sun Jan 14 10:57:01 2018 -0800
> ...
>
> Actual result:
> Suppose that cygwin git is specified, the result becomes:
> exit status 128 fatal: ambiguous argument '@u': unknown revision or
> path not in the working tree.
>
> Version:
> git version 2.15.1.windows.2
> git version 2.15.1
>
> I'm not certain if this is a git problem, as I could not reproduce
> this problem using python to script cygwin git.
>
> A list of scenarios I've tested are
> 1. golang + cygwin git = "exit code 128"
> 2. golang + windows git = "exit code 0"
> 3. python + cygwin git = "exit code 0"
> 4. python + windows git = "exit code 0"
>
> I've tried to write a simple program to echo the command line
> parameters passed by go into the process it executes - and it appears
> that go itself does not change "@{u}" into "@u". I'm a bit stuck at
> point to figure out which may be the cause: golang or git. I figured
> I'd start here.
>