Re: Some developement questions

[hw <hw@adminart.net>]

Michael Albinus <michael.albinus@gmx.de> writes:

> hw <hw@adminart.net> writes:
>
> Hi,
>
>> Well, I don't really know the datails; only sometimes I need to run
>> (tramp-cleanup-all-connections) when it somehow gets screwed up.
>>
>> Last time, it blocked me entirely when it tried to create a backup file
>> and couldn't do that because file permissions did not allow it.  I was
>> forced to either kill Emacs or change permissions so it could create the
>> file.  After that, I changed the backup directory for tramp and found
>> out that cleaning up all the connections is not enough to have this
>> change applied; I had to kill the buffer and visit the file again for it
>> to work.
>
> If this happens again, you could call "M-x
> tramp-cleanup-all-buffers". It clears all connections *and* kills all
> buffers related to a remote file.

Wouldn't that have killed a lot of buffers that do not require the
change of the autosave directory?

> For further analysis, I would need the Tramp debug buffer. If you set
> permanently tramp-verbose to 6, relevant information are traced. Well,
> at least as long Tramp is mulish ...

You could reproduce it maybe:  Edit a remote file in /usr/local/bin
which belongs to micheal:root.  Once Emacs tries to create an autosave,
tramp freaks out because it does not have permission to create the
autosave file in that place.

>> So at least for one case, here are the details, but I won't call it a
>> bug, only something that could be improved upon, like check permissions
>> before creating backups and prompt what to do when permissions do not
>> allow to create one, and applying a change of the backup directory right
>> away to all connections, or prompt the user if the change should be
>> applied to all of them now.
>
> Again, it is not clear what caused the problem. In order to get Tramp
> improved, I count on users sending the traces.

file permissions

I had to change the ownership of the directory so Emacs was allowed to
create the autosave file there to get around the problem.  After
changing the autosave location, I could give the directory back to root.

>> That was Emacs 24.x, on Centos, so perhaps this has already been
>> changed.
>
> Well, Emacs 26 is out, and the integrated Tramp shall behave
> better. Yes, this is my hope all the years ...

There's a way to find out :)