Build install kernel & Client with verifiable repos

[Quentin Stafford-Fraser]

Hi Thomas,

>
>> However, this doesn't work for me, because the class-specific keyring 
>> doesn't exist at this point, and 'apt-key add --keyring...' therefore 
>> fails.

> Can you please explain in more detail, why the class-specific does not
> exists for you? What do you mean by "at this point"? so it exists at a
> later point?

Sorry, that was bad phrasing!  It doesn't exist at all.

When the system finds a package_config/CLASS.asc key, the code is 
effectively doing this:

     apt-key add --keyring /etc/apt/trusted.gpg.d/CLASS.asc.gpg 
CLASS.asc

but this command fails with an error because 
/etc/apt/trusted.gpg.d/CLASS.asc.gpg does not exist.

It won't create it automatically.

My fix was just to 'touch' it because, as long as the keyring file 
exists, it's OK to start with an empty one.

All the best,
Quentin