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How to fetch newer foxy desktop packages?

asked 2020-06-23 15:29:00 -0500

FrankHx gravatar image

updated 2020-06-24 13:16:18 -0500

All right, here we go: I have a new desktop computer with Ubuntu 20.04 Focal Fossa installed. I want to run ROS2 on it, and it is supported by ROS2 Foxy. I had previously installed foxy desktop through the installation instructions, over two weeks ago. I followed the debian package instructions which can be found here

When revisiting it today, I found out I needed to install colcon. It returned 'Failed to fetch' commands when installing.

I thought re-installing Foxy would be a possible solution, so I uninstalled it through

sudo apt remove ros-foxy-desktop

And tried to re-install it. However, this returns package fetch failures as well! See below:

Err:1 http://packages.ros.org/ros2/ubuntu focal/main amd64 python3-rospkg-modules all 1.2.6-1
  404  Not Found [IP: 64.50.236.52 80]
E: Failed to fetch http://packages.ros.org/ros2/ubuntu/pool/main/p/python3-rospkg-modules/python3-rospkg-modules_1.2.6-1_all.deb  404  Not Found [IP: 64.50.236.52 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

I have tried both sudo apt-get update and running the command with --fix-missing. Both did not get me any further. I have even tried apt-get clean, then apt-get update but with the same result. I have also checked the Ubuntu software updater.

When navigating to the mentioned URL here it seems like that package has a newer version. The error mentions 1.2.6-1 while the site mentions 1.2.8-1... This was similar for the colcon package errors that I got earlier.

Additional information: uname -r returns kernel: 5.4.0-37-generic, architecture is amd64.

Is the package broken, or is it me? Can I do something about it? Should I simply wait for the packages and/or version information to be updated?

It feels like I am almost there, but I'm not getting anywhere at the moment. I hope someone can help and/or explain. If there is more information required, please mention it. Thanks in advance.

Best regards, Frank

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answered 2020-06-24 04:11:49 -0500

gvdhoorn gravatar image

updated 2020-06-24 04:15:19 -0500

I had previously installed foxy desktop through the installation instructions, over two weeks ago.

Please always include a link to any tutorials or instructions you refer to in your question text, as otherwise we cannot know which instructions you've followed.

As there are quite a few different ones, this is important information.

Is the package broken, or is it me? Can I do something about it? Should I simply wait for the packages and/or version information to be updated?

Have you ran a sudo apt update?

Package indices change as new packages are released.

You need to tell apt to update its internal copy of those indices, as otherwise it will try to fetch packages (ie: URLs) which don't exist any more.

You do that with a sudo apt update. Then try running your apt install command again.

Alternatively, the Ubuntu Software (or whatever it is called on Focal) and/or the Ubuntu software updates tool should alert you about the availability of updates.

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Thanks for your reply. I had already tried what you mentioned, and have edited my question accordingly.

FrankHx gravatar image FrankHx  ( 2020-06-24 13:20:17 -0500 )edit

I had already tried what you mentioned

Then it would have been good if you'd have included that in your OP.

In any case: does apt update return any errors?

Can you check to make sure you (still) have the correct key installed? #q325039 provides some info on how to check that.

gvdhoorn gravatar image gvdhoorn  ( 2020-06-24 13:26:57 -0500 )edit

I did not get errors with sudo apt update, although without sudo it complains about locking.. AFAIK apt commands should always be done with sudo, right? Anyway, I have performed the instructions of the question you referred to (updating the key), but the installation still fails on fetching python3-rospkg-modules...

FrankHx gravatar image FrankHx  ( 2020-06-24 13:38:39 -0500 )edit
1

Looking at packages.ros.org/ros2/ubuntu/dists/focal/main/binary-amd64/Packages and searching for python3-rospkg-modules does link me to pool/main/p/python3-rospkg-modules/python3-rospkg-modules_1.2.8-1_all.deb, so that would seem to be correct.

Something is not right on your machine.

Can you wget http://packages.ros.org/ros2/ubuntu/pool/main/p/python3-rospkg-modules/python3-rospkg-modules_1.2.8-1_all.deb?

Could you try a sudo apt clean && sudo apt update? Perhaps your local caches are corrupt somehow.

gvdhoorn gravatar image gvdhoorn  ( 2020-06-24 14:00:02 -0500 )edit

The wget command seems to work fine, I did not see errors. Somehow, it seems that after that wget and sudo apt clean && sudo apt update it went beyond fetching packages, and I have been able to install Foxy again successfully. Strangely I had already tried the clean and update before... Anyway, thanks! I have been able to install Foxy and installed and used colcon :)

FrankHx gravatar image FrankHx  ( 2020-06-24 14:10:29 -0500 )edit

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Asked: 2020-06-23 15:25:37 -0500

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Last updated: Jun 24