Problem: The repository ‘ impish Release’ no longer has a Release file.

Written by  on January 31, 2023

sudo sed -i 's/impish/jammy/g' /etc/apt/sources.list
sudo apt update && sudo apt full-upgrade

Manjaro Linux: “Account locked due to three failed login attempts..”

Written by  on November 24, 2022

So annoying ..
Edit /etc/security/faillock.conf with sudo and add deny = 0.

Today I handed in my first #ProductProposal 🥳

Written by  on August 29, 2022

And it was quite fun to write it.
Since pitching products is not my day-to-day business I spent some time to research how to write such a proposal. My first search results were aimed at “elevator pitches” or “startup pitches”. So I had to dig deeper ..

Anyway: due to confidentiality I can’t show-case anything here. I can only share this: I drew some #mockups with, put in the technical features and spent the majority of the time on writing a teaser. Something which will catch the audience immediately and makes them think: wow, we really have to sponsor this project!

Oh, why do I say “we”? #datamodul opened an innovation contest to source the ideas of their employees. Quite a clever idea. And a team can achieve so much more than a collection of individuals.

So .. even if that proposal is a dud, I learned some things, especially about writing a proper introduction. My first iteration was quite technical 😅

# Lessons learned:
* How to do a proper pitch, reduce technical details, appeal to a #vision, create a pitch deck with slides
* But also: go fast, break things. Too much time was spent on refinement and polishing. I had set myself an arbitrary date six weeks ago and in retrospective I had already 80% of the material at that time. I’ll be better next time: #time-boxing upfront.

Coursera: project management

Written by  on August 9, 2022

I’ve finished the “Foundations of Project Management” on the weekend. This is the first milestone out of six for the “Google Project Management: Professional Certificate”.

This was my first Coursera-online learning-experience and I liked it. A quite refreshing mix out of videos, quizzes and reading which kept me on track. Even finished some days earlier than anticipated by the regular four week-schedule 😅

I’ll definitely continue because my day-to-day business requires a lot of management .. and even with some hands-on experience, there is always the opportunity to improve.

The best weather app so far ;)

Written by  on August 5, 2022

People love forecasts. And almost everyone I know has one or two apps on their device to check it.
But nothing beats
while :; do clear; curl; date; sleep 60; done

ssh: unable to negotiate – not matching host key type found

Written by  on July 1, 2022

Unable to negotiate with port 22: no matching host key type found. Their offer: ssh-rsa

more details:
ssh -vvv root@

then fix by saying which type to use:
ssh -vvv -oHostKeyAlgorithms=+ssh-rsa root@

Else adapt the config. See


edit: since there was still a problem with deploying binaries to the target (embedded device), I’ve edited the ssh-config:

cat > ~/.ssh/config
Host 192.168.100.*
HostkeyAlgorithms +ssh-rsa
PubkeyAcceptedKeyTypes +ssh-rsa

Enter + CTRL+C, done :

Fresh Raspberry Pi 400, but package-manager ‘dead’

Written by  on March 10, 2022

It’s never early enough to inspire, so my firstborn got two days ago her first own computer. I don’t want that she grows comfortable with touching a smartphone, but not knowing what happens in the “back”, so she got a Raspberry Pi 400.
I did not expect that the red-white color-combination of the keyboard-like module with it’s raspberry-button will spark so much joy!
The first evening we unwrapped everything and she put all cables in and we booted it right from the preconfigured sd-card. Nice, very comfortable.

Then I wanted to run ‘apt-get’ to fix the updates and maybe install a paint-like program ..

Repository ‘ buster-updates InRelease’ changed its ‘Suite’ value from ‘stable-updates’ to ‘oldstable-updates’

So neither apt-get update or any of the first tips I checked, worked. Until I found this:
sudo apt-get update --allow-releaseinfo-change

Problem solved, but – would a newcomer or young person be able to fix this?
I doubt it. This isn’t really user-friendly ..

Anyway: Since update of the distribution from ‘buster’ to ‘bullseye’ by editing two package lists did not really go well, I’ve deployed a ‘real’ bullseye-image onto the sd-card and we fixed the rest of the configuration in minutes 🙂

external backups pt. II

Written by  on February 23, 2022

The worst archivist?
Of course, I know him.
It’s me.

So, some month ago I was writing about how to create and maintain some external backup [link] from data stored on the NAS.
I’ve also put some fancy commands, but when I wanted to do the scheduled refresh of the backup, I noticed, that my ‘documentation’ is without any value.
And this is due to continued iterations of the setup and the used commands, but not updating the documentation.


* activate the rsync-access on the DS213 via UI (else ‘permission denied’ is reported even when you can SSH in and check the rsync-version and then wonder what fails ..)
* plug the external HDD to the Raspberry Pi 3B

* run via VNC-remote-login in a bash on the RPi

rsync -avrh admin@ds213:/volume1/Photoshare_privat/ /media/pi/1.42.6-25556/Photoshare_privat/ && rsync -avrh admin@ds213:/volume1/homes/Marcel/ /media/pi/1.42.6-25556/homes/Marcel/ && rsync -avrh admin@ds213:/volume1/homes/ruzica/ /media/pi/1.42.6-25556/homes/ruzica/ && rsync -avrh admin@ds213:/volume1/homes/admin/ /media/pi/1.42.6-25556/homes/admin/ && rsync -avrh admin@ds213:/volume1/Camera/ /media/pi/1.42.6-25556/Camera/ && rsync -avrh admin@ds213:/volume1/photo/ /media/pi/1.42.6-25556/photo/ && rsync -avrh admin@ds213:/volume1/Musik/ /media/pi/1.42.6-25556/Musik/

to copy all relevant partitions

qmake: shared libs without versioning and symlinks

Written by  on October 12, 2021

By default share libraries have a symlink and versioning. To avoid this, add to respective *.pro:

iwyu: fatal error: ‘stddef.h’ file not found

Written by  on September 8, 2021

Include-what-you-use and Qt are not friends. iwyu-support in QtCreator is requested for a while, nobody cares.
So I installed it via apt; set an override to make and reran the build-process on a cleaned project:

Result: more than fifty errors like “fatal error: ‘stddef.h’ file not found”.
Some said that clang is missing (because that header is part of the installed package, my clang was 12 – iwyu was built against 11).
So the solution is: