emacs-lastpass and magit doesn't play well together

[mattiasb]

Hi!

I was trying to use the emacs-lastpass integration with auth-source to be able to store the github OAuth token that is created when setting up a github account with magit.

I get a Symbol's function definition is void: nil which I've tracked down to this line in ghub.el.

I'm not sure if this is a bug in emacs-lastpass or in ghub so I'm putting the issue here and pinging in @tarsius .

[tarsius]

I believe having users calling that function and backends returning that function is what auth-source expects. It's a bit weird. See "Help for developers" in the manual.

[mattiasb]

I have no more experience with auth-source than from what I read
yesterday trying to debug this, but this part from the
auth-source-search-documentation suggests otherwise:

The token can hold a :save-function key. If you call that, the
user will be prompted to save the data to the backend. You can’t
request that this should happen right after creation, because
‘auth-source-search’ has no way of knowing if the token is
actually useful. So the caller must arrange to call this function.

(Emphasis mine)

My take, from reading that, is that the :save-function key is optional.
Maybe because the auth-source author wanted to support read-only
backends? I really have no clue here.

Regardless it seems to me that emacs-lastpass should learn how to
save stuff if this is indeed missing.

[storvik]

Thanks for providing some pointers. As soon as I get back to my Linux computer I'll check it out!

[tarsius]

I have interpreted "can" as "if the backend supports storing passwords persistently, then it must return a function so that the caller can call that if and only if it wants to do that. Otherwise it cannot, and therefore does not have to, return such a function."

With that interpretation ghub's behavior is correct in that using a backend that does not allow storing the token persistently is of no use to it.

But there are at least two third-party backends that just save the secret instead of a saver function, so I'll probably handle that case in ghub.

[mattiasb]

I got all this working with the new forge package. My guess is that ghub changed somewhat or that I did something weird back then but it all works fine now.

[tarsius]

Yes, I changed something in ghub a while back, probably April. But I forgot to mention it here.