Using Emacs 27.2 on Slackware 15
I am trying to use su or sudo through Tramp to edit /boot/efi/EFI/Slackware/elilo.conf which is write protected on my EFI partition. I am able to login as root successfully, but when saving changes on this file in particular Tramp gives me this error in the messages buffer:
Tramp: Opening connection for root@slackpad.local using su...
Tramp: Sending command ‘exec su - root’
Tramp: Waiting for prompts from remote shell...
Tramp: Sending Password
Save auth info to file ~/.authinfo? [y/n/N/e/?] n
Tramp: Waiting for prompts from remote shell...done
Tramp: Found remote shell prompt on ‘slackpad.local’
Tramp: Opening connection for root@slackpad.local using su...done
Tramp: Inserting ‘/su:root@slackpad.local:/boot/efi/EFI/Slackware/elilo.conf’...done
elilo.conf has auto save data; consider M-x recover-this-file
Tramp: Checking ‘vc-registered’ for /su:root@slackpad.local:/boot/efi/EFI/Slackware/elilo.conf...done
elilo.conf has auto save data; consider M-x recover-this-file
Saving file /su:root@slackpad.local:/boot/efi/EFI/Slackware/elilo.conf...
Renaming /su:root@slackpad.local:/boot/efi/EFI/Slackware/elilo.conf to /su:root@slackpad.local:/boot/efi/EFI/Slackware/elilo.conf~...done
Copying /tmp/tramp.genETK.conf to /su:root@slackpad.local:/boot/efi/EFI/Slackware/elilo.conf...
Copying directly failed, see buffer ‘*tramp/su root@slackpad.local*’ for details.
Copying /tmp/tramp.genETK.conf to /su:root@slackpad.local:/boot/efi/EFI/Slackware/elilo.conf...failed
Renaming /su:root@slackpad.local:/boot/efi/EFI/Slackware/elilo.conf~ to /su:root@slackpad.local:/boot/efi/EFI/Slackware/elilo.conf...done
tramp-error: Copying directly failed, see buffer ‘*tramp/su root@slackpad.local*’ for details.
The error mentions checking buffer `*tramp/su root@slackpad.local*`, but that buffer is empty
Troubleshooting I have tried:
1. I have no problems writing to this file or folder as root with `su -l` or sudo, using emacs/vim/nano/whatever
2. Using Tramp however, neither su or sudo works (`C-x C-f /su::/` or `/sudo::/`)
3. Running clean with `emacs -q` first before using Tramp did not help
4. Through Tramp I am able to use dired to create or edit files/folders in other write protected directories - I tried /root and /etc
Any thoughts?
***UPDATE:***
The problem seems to be limited to anything within my EFI partition at `/boot/efi/` . I can use Tramp to write/edit files anywhere else in my root partition, including /boot itself, but not /boot/efi or anything under that
For what it's worth, here is my entry in fstab (nothing unusual I think):
$ grep efi /etc/fstab
/dev/sda1 /boot/efi vfat defaults 1 0
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