apt-get error “E: Unable to correct problems, you have held broken packages.”

The problem you have encountered is basically the package, or dependencies that are conflicting or broken and are therefore “held”.

You can check what (if any) packages are held using the following command:

dpkg –get-selections | grep hold

or

apt-mark showhold

If there’s no packages, or no output. That means it’s probably a dependency […]

Testing Failed: “Failed: error: SBT did not send a reply to our request, perhaps it was killed or failed to start”

Activator error “Failed: error: SBT did not send a reply to our request, perhaps it was killed or failed to start”.

This may be because SBT isn’t installed, SBT is a “simple build tool” for scala which isn’t packaged with the main binaries. You can download and install the latest SBT from the official […]

what(): Serial Port failed to open: open: Permission denied

what(): Serial Port failed to open: open: Permission denied

Trying to get access to your serial port without the need for running whatever program as sudo or root? You’re probably not in the dialout group, if that’s the case, here’s the fix:

First, check you aren’t in the group:

groups alex

This will list […]

AL lib: pulseaudio.c:331: PulseAudio returned minreq > tlength/2; expect break up – Ubuntu 11.10

./blender connect failed: No such file or directory ndof: spacenavd not found AL lib: pulseaudio.c:331: PulseAudio returned minreq > tlength/2; expect break up Floating point exception

Download and install the associated package to your processor from here : https://launchpad.net/ubuntu/oneiric/+package/python-openal

Restart your computer and the issue should now be resolved.

OpenNI – error CS0006: cannot find metadata file `System.Windows.Forms.dll’

During installing the OpenNi kinect drivers, found here: https://github.com/OpenNI/OpenNI, I came across this error:

make[1]: Entering directory `/home/alex/kinect/OpenNI/Platform/Linux-x86/Build/Samples/SimpleViewer.net’ gmcs -out:../../../Bin/Release/SimpleViewer.net.exe -target:winexe -unsafe -o+ -r:OpenNI.net.dll -r:System.Windows.Forms.dll -r:System.Drawing.dll -lib:../../../Bin/Release ../../../../../Samples/SimpleViewer.net/*.cs ../../Res/AssemblyInfo-OpenNI.cs error CS0006: cannot find metadata file `System.Windows.Forms.dll’ Compilation failed: 1 error(s), 0 warnings make[1]: *** [../../../Bin/Release/SimpleViewer.net.exe] Error 1 make[1]: Leaving directory `/home/alex/kinect/OpenNI/Platform/Linux-x86/Build/Samples/SimpleViewer.net’ make: *** [Samples/SimpleViewer.net] […]

ROS – rviz X Window System error.

rosrun rviz rviz [ INFO] [1322561467.803234807]: rviz revision number 1.6.7 [ INFO] [1322561467.803351442]: ogre_tools revision number 1.6.2 [ INFO] [1322561467.803374070]: compiled against OGRE version 1.7.3 (Cthugha) [ INFO] [1322561467.946771146]: Loading general config from [/home/alex/.rviz/config] [ INFO] [1322561467.946953292]: Loading display config from [/home/alex/.rviz/display_config] [ INFO] [1322561467.972674791]: RTT Preferred Mode is PBuffer. The program ‘rviz’ received […]

Steam in Wine, Repeated Windows

After installing Steam on my linux machine in wine I noticed a really annoy bug, the windows of steam are tiled across my screen as shown in the screenshot below.

Fix:

I managed to fix this by opening up the ‘Configure Wine’ program that comes with wine and under the Applications tab switching from […]

GitHub: Agent admitted failure to sign using the key.

Upon testing my GitHub setup on my home computer I got the following error after inputting this:

ssh git@github.com

Returned:

Agent admitted failure to sign using the key. Permission denied (publickey).

You’ll need to run:

ssh-add ~/.ssh/id_rsa

Make sure to enter the passphrase for the ssh key you generated.

How To Fix: Error: Cannot retrieve repository metadata (repomd.xml) for repository: Dropbox. Please verify its path and try again

After installing dropbox from the RPM package availble on the site on a new Fedora 15 install, I was unable to use yum without coming across this error:

$ update Loaded plugins: langpacks, presto, refresh-packagekit http://linux.dropbox.com/fedora/15/repodata/repomd.xml: [Errno 14] HTTP Error 404 – Not Found : http://linux.dropbox.com/fedora/15/repodata/repomd.xml Trying other mirror. http://linux.dropbox.com/fedora/15/repodata/repomd.xml: [Errno 14] HTTP Error […]

Error: “end_request: I/O error, dev sr0, sector xxxxx” – Linux

Error:

end_request: I/O error, dev sr0, sector 537392

If you’re getting a similar error filling your screen once you’ve installed Ubuntu, don’t panic. It’s pretty common which is basically because Ubuntu (or any other Linux distro) can’t control your CD/DVD drive properly, it’s probably trying to open/close it but doesn’t know if it has […]