keybase error - "Make sure your gist is public." for a public gist

I have added the file generated by `keybase prove github` exactly to this gist https://gist.github.com/anuraguniyal/2947c446433684aa687af670bf2906c2

still keybase can't verify account
```
$ keybase prove github -o t
You already have a proof for anuraguniyal@github; overwrite? [y/N] y
Your username on Github: anuraguniyal
Please publicly post the following Gist, and name it keybase.md
▶ INFO Writing proof to file 't'...
▶ INFO Written.
Check GitHub now? [Y/n] Y
Permission denied! Make sure your gist is public.
Check GitHub again now? [Y/n] Y
Permission denied! Make sure your gist is public.
Check GitHub again now? [Y/n] Y
```

so what is wrong with my file?

proof that it is same as what keybase output was
```
$ diff <(curl -s https://gist.githubusercontent.com/anuraguniyal/2947c446433684aa687af670bf2906c2/raw/27760d07c76d94a4371fe912a97d4ef46307cc7f/keybase.md) t && echo same files
same files
```

Start by reproducing the failure with `keybase prove github -o t` and inspect the public gist at the URL in the report. Compare the generated `keybase.md` with the gist using the shown curl-and-diff check; done means the public gist is accepted and GitHub proof verification succeeds.

Written by the indexing model from the issue text.