hiro protagonist's questions

i have at least 2 issues with my webcam.

first: when i start it up there is no image. setting the resolution then helps as described in this answer.

what i could not resolve so far it that when i take a picture using cheese it can not be encoded and saved. in the terminal i get the error message

(cheese:1550224): cheese-WARNING **: 09:10:32.703: Output state was not configured: ../gst-libs/gst/video/gstvideoencoder.c(2281): gst_video_encoder_can_push_unlocked (): /GstCameraBin:camerabin/GstEncodeBin:image-encodebin/GstJpegEnc:jpegenc0

and the camera input in cheese disappears and is replaced by the message

There was an error playing video from the webcam

is my install missing a library or what can i do?

i am using a cloud service that provides a sync app which depends on fuse. when i try to install fuse i get

$ sudo apt install fuse
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following packages will be REMOVED:
  fuse3 xdg-desktop-portal xdg-desktop-portal-gtk
The following NEW packages will be installed:
  fuse
0 upgraded, 1 newly installed, 3 to remove and 0 not upgraded.
Need to get 27.0 kB of archives.
After this operation, 1’577 kB disk space will be freed.
Do you want to continue? [Y/n] 

which will remove fuse3 and xdg-desktop-portal (which has this effect).

is there a way to have both, fuse and fuse3 installed? or is there a different workaround?

using a fresh ubuntu 22.04 install i can no longer save or download any files in firefox. it did work when i first installed firefox, now it no longer does.

File -> Save page as

does not even open a window where i could select a destination directory.

using the "save as" button in the pdf viewer also does nothing at all.

i just started firefox in safe mode

$ firefox --safe-mode

and saw the error message

(firefox:9161): Gtk-WARNING **: 09:19:12.367: Can't open portal file chooser: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.portal.Desktop was not provided by any .service files

this (probably) goes for all snap applications. for me it was

• firefox
• keepassxc

i might have uninstalled fuse3 and xdg-desktop-portal when i installed fuse. see this question.

is there a way to install the current MEGAsync desktop client on ubuntu 22.04?

they offer megasync-xUbuntu_18.04_amd64.deb as the most recent version.

when i try to install it i get:

$ sudo dpkg -i megasync-xUbuntu_18.04_amd64.deb
Selecting previously unselected package megasync.
(Reading database ... 381862 files and directories currently installed.)
Preparing to unpack megasync-xUbuntu_18.04_amd64.deb ...
Unpacking megasync (4.6.6-3.1) ...
dpkg: dependency problems prevent configuration of megasync:
 megasync depends on libc-ares2 (>= 1.11.0~rc1); however:
  Package libc-ares2 is not installed.
 megasync depends on libcrypto++6; however:
  Package libcrypto++6 is not installed.
 megasync depends on libmediainfo0v5 (>= 0.7.56); however:
  Package libmediainfo0v5 is not installed.
 megasync depends on libssl1.1 (>= 1.1.1); however:
  Package libssl1.1 is not installed.
 megasync depends on libzen0v5 (>= 0.4.31-2~); however:
  Package libzen0v5 is not installed.

dpkg: error processing package megasync (--install):
 dependency problems - leaving unconfigured
Processing triggers for mailcap (3.70+nmu1ubuntu1) ...
Processing triggers for gnome-menus (3.36.0-1ubuntu3) ...
Processing triggers for desktop-file-utils (0.26-1ubuntu3) ...
Processing triggers for hicolor-icon-theme (0.17-2) ...
Errors were encountered while processing:
 megasync

libcrypto++8 is available, but not libcrypto++6. libc-ares2 is available. libssl1.1 has no installation candidate; libssl3 is available.

first installing

$ sudo apt install libcrypto++8 libc-ares2 libmediainfo0v5 libssl3

reduces the error message to

dpkg: dependency problems prevent configuration of megasync:
 megasync depends on libcrypto++6; however:
  Package libcrypto++6 is not installed.
 megasync depends on libssl1.1 (>= 1.1.1); however:
  Package libssl1.1 is not installed.

but still - i was not able to install the package.

i want to try out a few things on the ubuntu live-server (currently ubuntu-20.04.1-live-server-amd64.iso from https://releases.ubuntu.com/).

it would be much easier for me to be able to log into that live system over ssh. i could also imagine using that as a rescue system in the future (yes, there may be better options for that).

i was looking around on the system a bit (# cat /etc/shadow) and found that the only (pre-installed) user that has a password set is installer.

what is this user's password? (if that is public it should be somewhere in the docs but i could not find it so far...)

In my office environment we have several systems that are not connected to the internet. Using apt-mirror I am able to make Ubuntu repositories and PPAs available to all the machines on this "offline" network.

Is there something similar for snap?

is there a way to lock a login console of a server after a certain time of inactivity? just lock; not log the user out.

if found vlock (and physlock) that seems to do a decent job of locking the login session. but is there a way to invoke it after a given time of user inactivity? i only can invoke it right now and its timeout flag does not seem to do what i need.

this seems to be a way on how to do it in zsh; but i'd need something in bash.

also note: i am not concerned about ssh sessions. and this is about servers (without any X installed).

UPDATE i know about TMOUT. i do not want to log the user out, i just want to lock their screen.

(also posted the question over at serverfault.com)

i installed spyder3 and tried to add its launcher to the gnome panel. i could not get this to work... i tried several things:

1. i launched spyder3 and clicked on its icon in the panel hoping for an 'Add to Favourites' menu item - there is none.

2. i looked for a .desktop file ($ dpkg -L spyder3 | grep '\.desktop'). it exists and is located at /usr/share/applications/spyder3.desktop. i tried to drag+drop that to the panel. that did not work either.

3. i tried to add spyder3.desktop on the command-line to the settings favourites (something like $ gsettings set org.gnome.shell favorite-apps "['firefox.desktop', ..., 'spyder3.desktop']"). logged out & in again. also that did not work.

4. i tried to create a custom spyder3 launcher using $ gnome-desktop-item-edit. that does create an (executable) .desktop file but i could not add it to the launcher either.

is there a way to add a launcher for spyder3? how?

i am doing incremental snapshots with btrfs using btrfs send and btrfs receive

assuming i start from an initial snapshot snapshot_0 and send the data to a file

$ sudo btrfs send snapshot_0 -f snapshot_0.data

then make some changes, create a fresh snapshot snapshot_1 and take a differential snapshot along the lines of

$ sudo btrfs send -p snapshot_0 snapshot_1 -f snapshot_0-1.data

now i have the two files snapshot_0.data and snapshot_0-1.data. i know i can use

$ sudo btrfs subvolume show snapshot_0
$ sudo btrfs subvolume show snapshot_1

in order to get the UUID and the Parent UUID (or Received UUID) from the actual snapshots.

my question is: is there a way to get these UUIDs from my data files snapshot_0.data and snapshot_0-1.data?

update: i just found Design Notes on Send/Receive.

2nd update: btrfs-snapshots-diff.py [github.com] may provide just that; investigating...

(i also posted the question over on unix.stackexchange.com).

when installing ubuntu-server on a new laptop the default font of the installer and the BusyBox console is extremely small. is there a way to make it bigger while the system is running from a boot .iso?

there is a setfont command but i have not found out how to use it (yet?).

update: i got a little further but the font remains unchanged. what i did:

# udpkg -i /cdrom/pool/main/c/console-setup/console-setup-linux-fonts-udeb_*_all.deb
# # maybe 'udpkg -c ...'?
# cd /usr/share/consolefonts
# gunzip Lat38-VGA16.psf.gz  # or some other font
# setfont Lat38-VGA16.psf

the last update of thunderbird (the version is now 52.1.1 (64-bit)) on ubuntu 16.04 causes my mail client to get stuck with the message

Status: Creating mail message...

then nothing happens anymore. i can cancel but not send the mail again... this happens often. i then have to start a new message and try again until the message is sent.

is there a fix for that? is that a bug? i have not changed anything in the configuration of the mail accounts since the update.

update: as Debora Weber-Wulff pointed out this may be an enigmail related issue only. (confirmed!)

update: there is a bug report for enigmail.

i tried to change the static ip address of one of my servers on the command line - and failed!

the original /etc/network/interfaces looks something like this

auto enp2s0f0
iface enp2s0f0 inet static
        address     192.168.0.57
        netmask     255.255.255.0
        gateway     192.168.0.1

auto enp2s0f1
iface enp2s0f1 inet static
        address     192.168.1.57
        netmask     255.255.255.0

and the configuration is ok when i boot the system. now i tried to change the subnet of the second interface to 192.168.10. i edited /etc/network/interfaces and tried to get the interface to accept this new configuration.

but no combination of

$ sudo systemctl restart networking.service
$ sudo ifdown enp2s0f1 && sudo ifup enp2s0f1
$ sudo ifconfig enp2s0f1 down && sudo ifconfig enp2s0f1 up

changes the ip address of that interface.

i am not sure if this is related to this bug or if i'm misunderstanding the new systemctl-way of restarting services.

on ubuntu 12.04 this just worked fine.

just rebooting the machine works fine. but it must be possible to reload and apply the information in /etc/network/interfaces (i even tried ifup with the flag -i /etc/network/interfaces - to no avail).

UPDATE:

as stated in this unanswered question: this works (but seems very clumsy):

$ sudo ifdown enp2s0f1
$ sudo ip addr flush dev enp2s0f1
$ sudo ifup enp2s0f1

is there really no simpler way in ubuntu 16.04?

the question may be a little impatient... but february 9th is over in every timezone; and this is the announced release date for 16.04.2.

but on the official download page 16.04.02 is not (yet) available.

has there been an announcement of an additional delay? or is it just my impatience that is getting the better of me?

UPDATE (Tue Feb 14 11:42:15 UTC 2017; i.e. feb 14 in all timezones)

as stated by answers below:

$ lsb_release -av
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.2 LTS
Release:    16.04
Codename:   xenial

an installed system will update itself to Ubuntu 16.04.2 LTS but there are still no .isos on the official download page.

the status on the qa site does not look promising yet...

UPDATE (Fri Feb 17 2017 11:00:00 UTC)

Updated ISO files have finally been released. You can now download the .iso files for both desktop and server editions.

is there a way i can change the DNS server on the command-line without having to change anything on the disk?

i recently booted into the rescue session and i got an IP address (using DHCP) but no DNS server. as my network config is usually done with the nm-applet in the desktop session and not in /etc/network/interfaces i would like to be able to provide a DNS server just for this rescue session and not write anything on disk.

this is usually possible by editing /run/resolvconf/resolv.conf. but resolvconf seems not to be running in the ubuntu 14.04 rescue session.

i was hoping there was something similar to the network configuration where i can configure an interface without having to edit a file:

# ifconfig eth0 192.168.2.5 netmask 255.255.255.0
# route add default gw 192.168.2.1

is there a way to do this for DNS in a rescue session on ubuntu 14.04?