How to fix APT Skipping acquire of configured file ... doesn't support architecture i386

N: Skipping acquire of configured file 'universe/binary-i386/Packages' as repository 'https://josm.openstreetmap.de/apt noble InRelease' doesn't support architecture 'i386'
```plaintext {filename="josm.openstreetmap.de"}

for one or more repositories.

## Solution

Your package manager is configured to use both `amd64` and `i386` repositories. The repositories for which you see the warning message don't support the `i386` architecture and only provide packages for `amd64`.

In order to fix this, edit the file for the repository in `/etc/apt/sources.list.d`. The name of the file in that directory is user-defined, if you can't find it, `grep` for the repository URL in the directory. For our example above:

```sh {filename="find_repo_grep.sh"}
grep -r "https://josm.openstreetmap.de/apt" /etc/apt/sources.list.d
```plaintext {filename="sources.list.d"}

The resulting output will tell you the correct file in the first column:

```text {filename="grep_output.txt"}
/etc/apt/sources.list.d/josm.list:deb [signed-by=/usr/local/share/keyrings/josm-apt.gpg] https://josm.openstreetmap.de/apt noble universe
```plaintext {filename="grep_output.txt"}

In this case, the correct file is `/etc/apt/sources.list.d/josm.list`.

Now, open this file in an editor (as root!), e.g.

```sh {filename="edit_josm_list.sh"}
sudo nano /etc/apt/sources.list.d/josm.list
```plaintext {filename="josm.list"}

The file will look like this, with or without the `[]` section

```text {filename="josm.list"}
deb [signed-by=/usr/local/share/keyrings/josm-apt.gpg] https://josm.openstreetmap.de/apt noble universe
```plaintext {filename="josm.list"}

Now, add `arch=amd64` to the square brackets `[]`. In case the square brackets are missing, add them directly after `deb`:

```text {filename="josm.list.fixed"}
deb [arch=amd64 signed-by=/usr/local/share/keyrings/josm-apt.gpg] https://josm.openstreetmap.de/apt noble universe
```plaintext {filename="josm.list.fixed"}

The order does not matter, but the `arch=amd64` must be inside the square brackets!
What we just did is to tell APT to only use the `amd64` architecture for this repository.

After that, save the file (Ctrl+O in nano) and exit the editor (Ctrl+X in nano).

Now you can run `apt update` again and the warning message should be gone - you might need to repeat this step for other repositories with the same warning, though.