Publish a nuget package on Appveyor feed

I have a C# solution building on Appveyor and the final artifact is a nuget package.

I'd like to have such package published in the custom Appveyor package feed.

I tried modifying the appveyor.yml file like this:

version: 1.0.{build}
branches:
  only:
  - develop
image: Visual Studio 2015
build:
  verbosity: minimal
deploy:
  - provider: NuGet
    symbol_server: https://ci.appveyor.com/nuget/dataparsers-xxxxxxxxxx/api/v2/package
    api_key:
      secure: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
    artifact: /.*\.symbols\.nupkg/

but it doesn't work. The yml file is not parsed correctly (error at line 8: "deploy" basically)

Moreover, where I do specify the package name?

https://www.appveyor.com/docs/nuget/#configuring-appveyor-nuget-feeds-for-your-builds

EDIT

Actual error:

Error parsing appveyor.yml: (Line: 8, Col: 2, Idx: 106) - (Line: 8, Col: 2, Idx: 106): While parsing a block mapping, did not find expected key.

Solution

That is correct YAML, so the most likely problem is that there is a Tab character in the sources that makes the indentation visually look good, but confuses the (indent) character count that the parser is using, as it doesn't know how to expand a Tab (4 spaces, 8 spaces, etc.)