Develop Reference

Can't install Hyperledger Sawtooth due to strange python dependency

I am trying to install sawtooth on my almost fresh installation of Ubuntu 20.04. I added the latest sawtooth repository and I used the following command:
sudo apt install sawtooth
It gives me the following output:
Building dependency tree...
Reading state information...
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
sawtooth : Depends: python3-sawtooth-cli but it is not going to be installed
Depends: python3-sawtooth-intkey but it is not going to be installed
Depends: python3-sawtooth-rest-api but it is not going to be installed
Depends: python3-sawtooth-sdk but it is not going to be installed
Depends: python3-sawtooth-validator but it is not going to be installed
Depends: python3-sawtooth-xo but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
Digging in to those packages, I reach the following package:
Reading package lists...
Building dependency tree...
Reading state information...
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
python3-secp256k1 : Depends: python3 (< 3.7) but 3.8.2-0ubuntu2 is to be installed
E: Unable to correct problems, you have held broken packages.
This error message is honestly insane to me. I have Python 3.8.10, so this shouldn't be a problem.
I was wondering if there is a known fix. I have looked at existing more general solutions to this, but they don't seem to work.
EDIT: To check my sanity on this, I created a completely fresh install of Ubuntu 20.04 on a virtual machine. I did nothing on the machine except what is in the guide below. I encountered the exact same error. This is a completely unaltered machine.
https://sawtooth.hyperledger.org/docs/core/releases/latest/app_developers_guide/ubuntu.html

Python: Showing unmet dependencies error and broken packages error despite not having any such packages

We were trying to run a shell script for installing prerequistes(install_prerequistes_onnx.sh) for OpenVINO Model Optimizer but we got the following error:
The Error
We tried resolving it using python 3.6.7 in a virtual environment(tsc). But it was of no use. Also we do not have any broken packages(we checked for them explicitly) but it still shows "unable to correct problems, you have held broken packages".
Can anyone explain the last three lines of the error? Also what does "error in line 78" imply, since our notebook was running fine before incorporating OpenVINO.
PS: We are using Ubuntu 18.04.

Please ensure that you’ve installed external software dependencies.
You may refer to this link for the installation:
https://docs.openvinotoolkit.org/2021.3/openvino_docs_install_guides_installing_openvino_linux.html#install-external-dependencies
For your virtual environment, the broken packages error that you’re facing is due to the Python’s dependency package version is not available on your system.
Try with this command: sudo apt update && sudo apt upgrade
If the issue still persists, you may need to re-install Python.

nodejs ask python-minimal that no longer use on python2

i use linux
nodejs had no problem untill i upgraded my system (sudo apt upgrade)
now when i try to install nodejs it say python-minimal mot installed
then i knew that it casue of updating python from python2.7.17 to python2.7.18 and python minimal is no longer require ,but now i cant install nodejs cause it ask for python-minimal
can any one help me
the problem is when i want to install nodejs 15 or 14
but when i install nodejs 12 or lower it have no problem
this is what it say after i write (sudo apt install nodejs)
sudo apt upgrade nodejs
[sudo] password for julian:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
libnode72 : Conflicts: nodejs-legacy
nodejs : Depends: python-minimal but it is not installable
E: Broken packages

This
sudo apt remove libnode72:amd64
sudo apt autoclean
sudo apt autoremove
should do the job.

I encountered this issue today after going from Ubuntu 18.04 to Ubuntu 20.04 and there are a lot of old Ask Ubuntu questions surrounding this and Github questions where for one reason or another various apps (Node included) rely on core Python functions that are leveraged from the python-minimal library.
For better or worse it also doesn't seem to care if Python is installed or not in it's entirety. It wants the minimal package specifically.
The thing is all the python-minimal repositories are marked OldStable (about OldStable if you want to know)and rely on Python 2 which has been sunset.
It seems if you haven't upgraded your OS in a while there is something hanging out in the package manager that will tell you that node needs python minimal to be run or installed but this is not the case as is evident by the lack of package support.
The solution I found was after upgrade to simply rerun the installation for Node based on the package manager instructions for your operating system. In my case it was specifically Dedbian and Ubuntu based distributions.

python package error in installation time

I am installing python and some other python packages. I am getting same error.
suggest me some. how can I fix.
palwesh#wg-palwesh:~$ sudo apt-get install python-pip
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
python-pip : Depends: python-pip-whl (= 9.0.1-2) but 9.0.1-2.3~ubuntu1.18.04.1 is to be installed
Recommends: python-all-dev (>= 2.6) but it is not going to be installed
Recommends: python-setuptools but it is not going to be installed
Recommends: python-wheel but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
palwesh#wg-palwesh:~$

First try sudo apt-get update to make sure your package lists are up to date.
"Unable to correct problems, you have held broken packages." implies that you have used Apt's hold functionality to stop packages from being updated. (apt-mark showhold shows you the held packages, apt-mark unhold lets you remove relevant holds.)

cant install lirc due to higher python version

Okay so i got i PiFace2 and i am trying to install pifacecad but you need pyton3lirc but this is what i am trying
pi#raspberrypi:~ $ sudo apt-get install python3-lirc
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
python3-lirc : Depends: python3 (< 3.5) but 3.5.3-1 is to be installed
E: Unable to correct problems, you have held broken packages.