"kubectl exec" in Cygwin gets "Upgrade request required", but not in cmd shell

[David Karr]

On Sat, Jun 13, 2020 at 10:31 PM Marco Atzeri via Cygwin wrote:

> On 13.06.2020 20:53, David Karr via Cygwin wrote:
> > I've been using kubectl in Cygwin on Windows 10 for quite a while, to
> > communicate to our in-house k8s clusters. I often use "kubectl exec" to
> > open a shell in a container or directly execute a shell command.  This
> has
> > worked perfectly fine for a long time.
> >
> > A couple of days ago, I discovered that all of these attempts were
> failing
> > with "Upgrade request required".  I hadn't upgraded kubectl or Cygwin in
> > quite a while. I doubt our clusters had a k8s upgrade, but it's entirely
> > possible.
> >
> > A colleague of mine has a very similar desktop configuration (Windows 10,
> > Cygwin), and he's not seeing this symptom.
> >
> > I noticed that when I ran "kubectl exec" with max verbosity, it shows the
> > resulting "curl" command that it runs. I tried that resulting command,
> and
> > it results in the same response. I then tried updating my Cygwin tools
> and
> > retesting, no change.
> >
> > I then took the entire resulting "kubectl exec" command line and ran it
> in
> > a "cmd" shell.  No problem at all.  No error.
> >
> > I know I haven't provided much useful information yet. I wanted to get an
> > initial response before I started providing those diagnostics. Is there a
> > clear issue here that I'm not aware of?
> > --
>
> from where is kubectl coming from ?
>
> In cygwin I found only a kubectl.py in the ansible package
>

It's from here:
https://kubernetes.io/docs/tasks/tools/install-kubectl/#install-kubectl-on-windows
.