Add tool package format version metadata to packed tool in settings file

To support better error message when future version come.

@KathleenDollard should it be SettingsVersion? it is really not about settings file. It is the format or structure(folder structure + setting file content). Maybe ToolPackageFormatVersion ?

example:

<?xml version="1.0" encoding="utf-8"?>
<DotNetCliTool>
  <Commands>
    <Command Name="mytool" EntryPoint="mytool.dll" Runner="dotnet" />
  </Commands>

  <SettingsVersion>1.0.0</SettingsVersion>
</DotNetCliTool>

And also, warning when it is not compatible (start with 1.)

cc @dotnet/dotnet-cli

• change on CLI to warning when major version is different
• change on SDK to put version on packtool

[wli3]

@nguerrera @KathleenDollard

Let’s move the discussion on PR here. Since it is more of a general issue https://github.com/dotnet/sdk/pull/2074#issuecomment-375136901

Nick:

I don’t have a huge opinion on this, but if the sole purpose is to mark a breaking boundary for older consumers, we could just use a single number: “1” -> “2” -> “3”.

I just wonder when we’re expected to change major, minor, patch if there are 3 parts.

Whatever scheme we use, we should be documenting when to change it.

[KathleenDollard]

Can you write the code so it ignores all but the first digit, but doesn’t crash if we need two digit numbers later.

If we don’t prepare for the possibility of two digits, then we would be forced to add another number if we are wrong and it matters what the version is, even when the change is additive and non-breaking.

Does that make sense? Otherwise I will be here a bit longer if you want to come by.