Re: feature/package-vc has been merged

[Philip Kaludercic <philipk@posteo.net>]

(sorry, this message got sent out too early.  Continuing my reply here)

> 3. Try to install Modus Themes
>
>    Update the configuration from `package' to `package-vc':
>    
>      (with-eval-after-load 'package-vc
>        (add-to-list 'package-vc-selected-packages 'modus-themes))
>    
>    Delete `modus-themes-<version>' from `~/.emacs.d/elpa'.
>    
>    Restart Emacs.
>
>    Got:
>    
>      user-error: Unknown package to fetch: nil
>
>    *scratches head*
>    
>    Oh, the list!  Change the configuration again:
>    
>      (with-eval-after-load 'package-vc
>        (add-to-list 'package-vc-selected-packages '(modus-themes)))
>    
>    Restart Emacs.

Two ways to resolve this:  Either throw an error earlier, which might be
annoying but the right thing™, or dwim and accept that the value might
not be readable in ECI.

>    Got:
>    
>      run-hooks: Symbol’s function definition is void:
>      modus-themes-load-operandi
>    
>    Check `~/.emacs.d/elpa' to see if it contains `modus-themes'.
>
>    It does.
>    
>    *scratches head*
>    
>    Check `package-vc-selected-packages':
>
>      Its value is ((modus-themes))
>    
>    Try `M-x package-vc-update'.
>
>    Got:
>    
>      completing-read-default: Wrong type argument: stringp, t
>
>    Check `load-path' if it contains `modus-themes'.
>
>    It does.
>    
>    Execute `M-: (require 'modus-themes)' followed by `M-x
>    modus-themes-load-operandi'.
>
>    The theme loads.
>
>    *scatches head*
>    
>    Think: "It seems that Emacs needs to process auto-loads."
>    
>    Tries `package-refresh' again.
>
>    Got:
>    
>      completing-read-default: Wrong type argument: stringp, t

This issue should be resolved with the above patch, but the question
still remains what went wrong in the above installation.  Can you
check/post the -pkg.el and -autoloads.el file?

> 4. Give up and report back.
>
>    :)
>
> Amost there!
>
>> Ah ok, but that is to be excepted for now.  I am not part of the MELPA
>> project, so I can't "force" them to provide package specifications.
>> If they are missing, then we must rely on heuristics to download
>> source packages.  My hope is that they will add the file too at some
>> point.
>
> I see.  One can still install MELPA packages via a URL, right?

package-vc.el (just like package.el) doesn't treat MELPA packages as
special or different.  If you give `package-vc-install' a URL, it will
try to guess what has to be done -- this doesn't always work, but the
guessing can still be improved.

What you can do with `package-vc-selected-packages' is give your own
ELPA-esque specification.  That should work most of the time if a
package is not available on GNU ELPA or NonGNU ELPA.

> P.S. 1
>
> I remain unsure what `refresh' means.  According to the documentation,
> it "refresh[es] the installation for [the] package".  But what does it
> mean?  The command needs a more detailed documentation and perhaps also
> a more descriptive name.  I understand the `update', but not the
> `refresh'.

Did the above docstring clarify that point?

> P.S. 2
>
> I could not find `package-vc-update-all' akin `package-update-all'.  Not
> that I needed it, but I looked for it in the case I manage to install
> more packages.

It doesn't exist.  My idea was that package-update-all would handle
that, but there might be a value in a command that only updates source
packages?

> P.S. 3
>
> The `package-vc-selected-packages' documentation still does not link the
> `package-vc-archive-spec-alist' variable.  But I noticed that the
> variable has a new name, with a double dash for private use.  Either
> way, I just wanted to mention this fact for completness.

As mentioned above there are a few commits I haven't been able to push
because emacs.git is preventing me from force pushing.  I'll try to get
them up there some other way, and then rewrite the history before
rebasing the changes onto master.

> Rudy