Igor Zinov'yev's questions

I'm trying to package software for the Cardano blockchain using Launchpad, and so far I have been able to create a PPA with the required libsodium fork. This fork is required to build the Cardano node software, which was my next step - to build it and put it on the PPA as well. The problem is that in order to build the node software, the builder needs to use that PPA to be able to install the proper dependency.

Without it, I get build failures like this, where it fails to resolve the needed version:

The following packages have unmet dependencies:
 sbuild-build-depends-cardano-node-dummy : Depends: libsodium-dev (= 1.0.17.1-0ubuntu1) but 1.0.18-1 is to be installed
E: Unable to correct problems, you have held broken packages.

I have tried making the PPA a depedency, but apparently you can't do that because the package is built as part of the same PPA, and it can't depend on itself. What do I do here?

Edit to clarify: I am trying to build a package in a PPA that depends on a package that comes from the same PPA.

I'm running Ubuntu 19.10, and I was following the instructions in the answer about how to add a higher resolution mode using xrandr, and I ran into a problem. What I need is to be able to use an external monitor with the 5120 by 2160 resolution. So I first ran cvt:

$ cvt 5120 2160
# 5120x2160 59.99 Hz (CVT) hsync: 134.19 kHz; pclk: 949.00 MHz
Modeline "5120x2160_60.00"  949.00  5120 5536 6096 7072  2160 2163 2173 2237 -hsync +vsync

Having that, I created the mode using xrandr:

$ sudo xrandr --newmode "5120x2160_60.00"  949.00  5120 5536 6096 7072  2160 2163 2173 2237 -hsync +vsync

After that I added the mode to the connected display:

$ sudo xrandr --addmode DP-1-1 "5120x2160_60.00"

It appeared in the output of xrandr:

$ xrandr
Screen 0: minimum 8 x 8, current 3440 x 2592, maximum 32767 x 32767
eDP-1-1 connected 2048x1152+720+1440 (normal left inverted right x axis y axis) 344mm x 194mm
   3840x2160     60.00 +  59.98    59.97  
   ... SNIP ....

DP-1-1 connected primary 3440x1440+0+0 (normal left inverted right x axis y axis) 800mm x 330mm
   3440x1440     59.97*+  59.96    49.99  

   ... SNIP ...

   5120x2160_60.00  59.99    <-- THIS IS THE MODE I NEED
DP-1-2 connected (normal left inverted right x axis y axis)
   2560x2160     59.66  
   640x480       59.94  
DP-1-3 disconnected (normal left inverted right x axis y axis)
  5120x2160_60.00 (0x290) 949.000MHz -HSync +VSync
        h: width  5120 start 5536 end 6096 total 7072 skew    0 clock 134.19KHz
        v: height 2160 start 2163 end 2173 total 2237           clock  59.99Hz

After that I'm trying to switch the monitor to that mode using Ubuntu's settings dialog, but I only get a black screen on the external monitor. What's funny is that I can see the mouse cursor on it, and it moves, but everything else is black, changing the mode back doesn't help - only turning the monitor off and on again gives me the image back. What should I do next?

Here's the output I get from lshw:

$ sudo lshw -C display
  *-display                 
       description: 3D controller
       product: NVIDIA Corporation
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:01:00.0
       version: a1
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list rom
       configuration: driver=nvidia latency=0
       resources: irq:182 memory:ec000000-ecffffff memory:c0000000-cfffffff memory:d0000000-d1ffffff ioport:3000(size=128) memory:ed000000-ed07ffff
  *-display
       description: VGA compatible controller
       product: UHD Graphics 630 (Mobile)
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 00
       width: 64 bits
       clock: 33MHz
       capabilities: pciexpress msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:151 memory:eb000000-ebffffff memory:80000000-8fffffff ioport:4000(size=64) memory:c0000-dffff

I happened to encounter a very weird problem. I'm running Ubuntu 17.10 in development mode since around April, and ever since I have been trying to stay on the latest kernel RC to avoid nasty problems with suspend and GPU that I've had on my Dell Precision.

Since I have installed 4.14-rc2, I suddenly lost WiFi connectivity. After running bisect I narrowed the problem down to a changeset in the kernel that has updated Apparmor.

Looking at journalctl -xe output I noticed that a lot of errors like that appeared:

Oct 27 14:45:48 precision audit[6088]: AVC apparmor="DENIED" operation="create" profile="/sbin/dhclient" pid=6088 comm="dhclient" family="unix" sock_type="stream" protocol=0 requested_mask="create" denied_mask="create"

Errors like this happened also for procceses mysqld, avahi-daemon and cups-browsed. I have disabled the profiles for these processes with the following command:

$ sudo ln -s /etc/apparmor.d/sbin.dhclient /etc/apparmor.d/disable
$ sudo apparmor_parser -R /etc/apparmor.d/sbin.dhclient 

And boom, I have WiFi back. But is this the right way to handle this situation? Should I modify the profiles instead, or submit a bug to Launchpad about it?

I have recently bought a new Acer V3-772G laptop and now I'm trying to install Ubuntu using a flash drive. This laptop has UEFI, but it can be disabled by switching to Legacy mode. I have done it to allow booting from a flash drive and when I boot it up, I can hear the Ubuntu welcome sound, but I can see nothing on the screen. It's not even purple or black, it looks like it is completely turned off.

Possibly it has something to do with one of the following:

• the laptop has the NVIDIA Optimus system with Intel 4600 and GeForce 760M adapters
• the flash drive has been created by Unetbootin instead of Ubuntu's native flash drive creation tool
• perhaps the UEFI legacy mode interferes with the boot process

I'm not sure what to do and how do I even start to diagnose what happens. Any help would be greatly appreciated!

I am using a separate HDD as a disk for my Virtualbox machine. I have made a vmdk using the tutorial provided in the VirtualBox manual, but in order for the machine to run I have to constantly change the owner and group of the /dev/sdb device to the user I am logged in with.

Time after time permissions get reset back to root:disk, and I'm not certain when exactly that happens. What can I do to change the owner and group permanently or maybe to not have to do it at all?

I am rather new to Unity, I have only started using it after upgrading to 11.10 several days ago, and one thing really worries me. I started to miss incoming messages in Empathy and Skype because sometimes I'm not there when they arrive. And when I'm back, I don't use the launcher because I have a maximized window, so I don't see that there are windows requesting my attention.

Is there a way to make the launcher remind me of such windows? Or maybe make it stick them out halfway like it does when an event happens and keep them like that until I click on them?

My colleague and me are often using skype to work together, but there is a problem that bothers me very much. When he is sharing his whole screen, I only receive it in a window that takes about a fourth part of my screen (about 50% size). Obviously, all text becomes unreadable.

We have the same horizontal resolution, but I have a 4:3 display, and he has a 16:9 display. So it's 1280x1024 against 1280x768, his screen should be able to fit into mine.

What's even stranger is that when I use a laptop I have, the screen is shared with me at 100% size. Both my PC and my laptop use Ubuntu 10.10.

Can something be done about it?

P.S. Maybe it has something to do with compiz?

Let me state for the record that I'm a total noob when it comes to Hi-Fi sound systems, but I am rather picky about the sound quality. Normally I listen to CD recordings ripped to FLAC in 16/44, but I have several albums that are also ripped from vinyls to FLAC in 24/96. But it seems that I can't tell the difference between 16-bit and 24-bit versions (except for some vinyl noises, of course). That can be due to several reasons:

• my equipment (onboard audio, monitor headphones) isn't good enough to make any difference,
• my system is not playing audio in 24-bit 96 kHz,
• I am physically unable to hear the difference.

So here is my question, how do I tell if my system can play 24-bit sound with 96 or 192 kHz resolution? And if it can, how do I tell that it plays it instead of downsampling to 16-bit / 44 kHz?

Also, what hardware (audio cards, amplifiers, etc.) would you recommend to play such recordings on Ubuntu?