Package 'netcat' has no installation candidate. How to fix this?

Docker Desktop for Windows
1

I’m using Docker Desktop 4.20.1 on Windows 11 using WSL2
This is my first time using Docker.
In Powershell at the root of my project I run

docker-compose up -d --build

The output is this:

> [api 2/6] RUN set -e;     apt-get update ;    apt-get -y install netcat ;    apt-get -y install gettext ;:
#0 0.856 Get:1 http://deb.debian.org/debian bookworm InRelease [147 kB]
#0 0.969 Get:2 http://deb.debian.org/debian bookworm-updates InRelease [52.1 kB]
#0 1.058 Get:3 http://deb.debian.org/debian-security bookworm-security InRelease [48.0 kB]
#0 1.152 Get:4 http://deb.debian.org/debian bookworm/main amd64 Packages [8904 kB]
#0 2.043 Get:5 http://deb.debian.org/debian-security bookworm-security/main amd64 Packages [30.4 kB]
#0 3.215 Fetched 9182 kB in 3s (3523 kB/s)
#0 3.215 Reading package lists...
#0 3.801 Reading package lists...
#0 4.344 Building dependency tree...
#0 4.494 Reading state information...
#0 4.501 Package netcat is a virtual package provided by:
#0 4.501   netcat-openbsd 1.219-1
#0 4.501   netcat-traditional 1.10-47
#0 4.501
#0 4.505 E: Package 'netcat' has no installation candidate
------
failed to solve: process "/bin/sh -c set -e;     apt-get update ;    apt-get -y install netcat ;    apt-get -y install gettext ;    apt-get -y  install httpie;     pip install --upgrade pip     pip install flask" did not complete successfully: exit code: 100

I’ve tried reinstalling Docker Desktop. I also know about trying apt --update then apt --install netcat However, I don’t know where I should do these commands. There isn’t a terminal available in the Docker application yet.

1 Like
2

This isn’t a Docker-specific issue, however, the warning

Package netcat is a virtual package provided by:
    netcat-openbsd 1.219-1
    netcat-traditional 1.10-47

is the root of your issue. On Debian, netcat isn’t a package, as two “variations” of netcat exist in the package repository. Instead, replace the apt install netcat with apt install netcat-traditional and it will be installed.

1 Like
3

Thank you for clarifying the error message.
Your solution worked!
I had tried changing it to netcat-traditional in the Dockerfile earlier today with no luck. I didn’t realize it needed to be changed in Dockerfile_app as well.
Thanks for the response. My apologies for the noob question.

4

Thanks for the tip the following did work ! :grinning:

apt install netcat-traditional