bug#14447: tramp-gvfs.el and xesam.el sometime fail to load

[Glenn Morris]

Package: emacs
Version: 24.3

I ssh'd into a remote machine where I had a graphical session running.
Now:

emacs -Q -nw -l xesam
emacs -Q -nw -l tramp-gvfs

both fail to load the associated library with error message:
D-Bus error: "No connection to bus", :session

Debugger entered--Lisp error: (dbus-error "No connection to bus" :session)
dbus-get-unique-name(:session)

It ought to always be possible to load lisp libraries.

[Michael Albinus]

I've wrapped the call of `dbus-get-unique-name' by
`ignore-errors'. tramp-gvfs.el returns now the user error "Package
`tramp-gvfs' not supported", which is intended.

xesam.el is obsolete (the XESAM interface is not used anymore by search
engines). Shouldn't we move xesam.el to "obsolete/"?

Best regards, Michael.

[Stefan Monnier]

>> It ought to always be possible to load lisp libraries.
> I've wrapped the call of `dbus-get-unique-name' by
> `ignore-errors'. tramp-gvfs.el returns now the user error "Package
> `tramp-gvfs' not supported", which is intended.

Not good enough: as Glenn wrote "It ought to always be possible to load
lisp libraries". They may be loaded for all kinds of reasons that have
nothing to do with using that library.

> xesam.el is obsolete (the XESAM interface is not used anymore by search
> engines). Shouldn't we move xesam.el to "obsolete/"?

Feel free to do it (but even in obsolete/, it should be always possible
to load this library).


Stefan

[Michael Albinus]

Stefan Monnier <mon...@iro.umontreal.ca> writes:

>>> It ought to always be possible to load lisp libraries.
>> I've wrapped the call of `dbus-get-unique-name' by
>> `ignore-errors'. tramp-gvfs.el returns now the user error "Package
>> `tramp-gvfs' not supported", which is intended.
>
> Not good enough: as Glenn wrote "It ought to always be possible to load
> lisp libraries". They may be loaded for all kinds of reasons that have
> nothing to do with using that library.

I understand this. However, there shall be an indication to the user
that all those (D-Bus based) Tramp methods are not available. How shall I
do it otherwise?

Well, maybe a warning. Would this be acceptable?

>> xesam.el is obsolete (the XESAM interface is not used anymore by search
>> engines). Shouldn't we move xesam.el to "obsolete/"?
>
> Feel free to do it (but even in obsolete/, it should be always possible
> to load this library).

For sure. I'll move it.

> Stefan

Best regards, Michael.

[Stefan Monnier]

> I understand this. However, there shall be an indication to the user
> that all those (D-Bus based) Tramp methods are not available. How shall I
> do it otherwise?

Don't do it when loading the file, but instead do it when calling
its functions.


Stefan

[Michael Albinus]

Done.

> Stefan

Best regards, Michael.