How do I set up and reference mlpack libraries in Ubuntu? - linux

I'm running Ubuntu 16.04, and I have to admit my Linux skills are weak and are probably the reason that I'm struggling here.
I've run the following commands successfully:
sudo apt-get install libmlpack-dev
sudo apt-get install mlpack-bin
What's confusing me is that I have no idea where mlpack has been installed to--I'm expecting to see some library files somewhere, as well as some source code for some examples.
In general, when you install libraries like this on Linux, is there one place where you can expect them to be found?
Thanks for helping out a novice!

I asked a colleague for help and got this figured out.
To summarize:
libmlpack-dev includes the libraries and header files but no source code examples. You can find a couple small code samples on their website, though.
The libraries are installed to the default location of /usr/lib/ and the headers to the default location of /usr/include/. The nice thing about this is that these folders are already on your path, so you're all set to #include the mlpack headers.
I wrote a blog post to describe all the steps for getting started with mlpack for Linux noobs like me :)

Related

install VMOD basic-auth for Varnish

Im trying to install the VMOD called basicauth.
This is the repo: https://git.gnu.org.ua/vmod-basicauth.git
There is also a README file which is supposed to help guide you through the process.
It tells you to pull the code, also pull code of varnish (did that with help of sudo apt-get source varnish )... I did that, so far so good.
But then Im supposed to do this:
run:
./configure --with-varnish-source=/usr/src/varnish-3.0.1 --with-vmod-dir
THE PROBLEM
I have been trying to figure out where to find that "configure" script. I have no idea where to find it.
When I look at other tutorials, like this one I guess that it should within the vmod-basicauth folder... but it is not. There is only configure.ac. It tried running that file, but that does not work. Does anyone of you know how I can install this VMOD? Any tips or help would be appreciated.
Also: it seems there is only information off very old tutorials and repos... any idea where I could some more up to date infos?
UPDATE
I have also downloaded "The Varnish Book" now, checked on how to isntall "libvmod-example." Within that folder there is a "autogen.sh" file that create the "configure" file. But I also cannot find a any "autogen.sh" in the basicauth package...
Hahha ..... arrrrrrr Im getting nowhere.
Does anyone know where I can find a good tutorial?
Im wokring with ubuntu-server currently. Noticed that redhad has VMODs in their repos, but that won't help me ;)
SYSTEM INFO
Here is some more info about my system:
dpkg -l | grep varnish
ii libvarnishapi-dev:amd64 6.2.1-2 amd64 development files for Varnish
ii libvarnishapi2:amd64 6.2.1-2 amd64 shared libraries for Varnish
rc varnish 6.2.1-2 amd64 state of the art, high-performance web accelerator
Serverifno (a local development VM in this case):
Best,
AuthenticPinguin
I just tested it, and I didn't experience any problems compiling the VMOD.
Here's a step-by-step guide on how to install it.
1. Get a recent Varnish version
I'm not sure whether or not you installed Varnish through the Ubuntu packages, but I advise you to install it via the official packages: https://packagecloud.io/varnishcache/.
2. Install the build dependencies
Install the required build dependencies by using the following command:
apt-get install -y varnish-dev autoconf automake gcc libtool make python3-docutils git
Most of these dependencies are trivial, but there's one specific package that might not be found unless you're using the official Varnish package repo. It's varnish-dev.
I've tried looking for it natively in the Ubuntu Focal repository, and the closest I came was libvarnishapi-dev, but that didn't really work.
That's why I advise using the official packages from https://packagecloud.io/varnishcache/. The version I prefer is https://packagecloud.io/varnishcache/varnish60lts, because it's the LTS version.
3. Get the source code
Once you've put all the dependencies in place, you can go ahead and download the VMOD source code by running the following commands:
cd /usr/src/
git clone git://git.gnu.org.ua/vmod-basicauth.git
As you can see the code will be place in the /usr/src directory.
4. Compile the code
Now that the source code is on your system, you run the following commands to configure, compile and install the VMOD code:
./bootstrap
./configure
make
make install
If ./configure cannot be found, it means it wasn't properly generated by the ./bootstrap command. If that happens, have a look at the output of your ./bootstrap command to figure out what went wrong.
5. Import the VMOD
The VMOD has been installed in the proper location, so it's time to import it into your VCL file and use its features.
Here's a VCL example:
vcl 4.1;
import basicauth;
sub vcl_recv {
if (!basicauth.match("/var/www/.htpasswd",req.http.Authorization)) {
return(synth(401,"Authentication required"));
}
}

Where can I get libGLU.so.1 on Arch Linux?

I'm running arch linux and am making an attempt to run DaVinci Resolve. Initially startup said nothing, it just timed out and closed. Then I found a recommendation to run it with /opt/resolve/bin/resolve this got me an error saying
libGLU.so.1: cannot open shared object file: No such file or directory
This has sent me on a wild goose chase trying to install libGLU.so.1 on my system. I heard somewhere it is part of mesa so I sudo pacman -S mesa and I've tried to find a AUR package that might have it but no luck. Even trying variations of yay libGLU and yay libGLU-mesa, no luck so far.
Additionally find / -name 'libLGU*' returned nothing even when ran with sudo, meaning it isn't already on my system in the wrong directory.
This might unfortunately be an instance where I download the file and place it where it needs to go but that's probably not in the best interest of the long term longevity of my system.
I'm probably fairly novice when compared to most others on linux but I think I've gotten a lot of the basics down. Would love any insight you may have on this issue!
While an outdated forum post said that /usr/lib/libGLU.so.1 is owned by the mesa package, it is now currently owned by glu.
pacman -S glu ought to give you your needed library.
For future reference, you can reverse search filename->package using pkgfile, which works even if you don't have the respective files/packages locally.
https://wiki.archlinux.org/index.php/pkgfile
$ sudo pkgfile --update
$ pkgfile libGLU.so.1
extra/glu
Alternatively there's the built-in pacman -F, but it's generally slower than pkgfile.

Deployement Qt error [duplicate]

I wrote application for linux which uses Qt5.
But when I am trying to launch it on the linux without Qt SDK installed, the output in console is:
Failed to load platform plugin "xcb". Available platforms are:
How can I fix this? May be I need to copy some plugin file?
When I use ubuntu with Qt5 installed, but I rename Qt directory, the same problem occurs. So, it uses some file from Qt directory...
UPDATE:
when I create in the app dir "platforms" folder with the file libqxcb.so, the app still doesnot start, but the error message changes:
Failed to load platform plugin "xcb". Available platforms are:
xcb
How can this happen? How can platform plugin be available but can't be loaded?
Use ldd (man ldd) to show shared library dependencies. Running this on libqxcb.so
.../platforms$ ldd libqxcb.so
shows that xcb depends on libQt5DBus.so.5 in addition to libQt5Core.so.5 and libQt5Gui.so.5 (and many other system libs). Add libQt5DBus.so.5 to your collection of shared libs and you should be ready to move on.
As was posted earlier, you need to make sure you install the platform plugins when you deploy your application. Depending on how you want to deploy things, there are two methods to tell your application where the platform plugins (e.g. platforms/plugins/libqxcb.so) are at runtime which may work for you.
The first is to export the path to the directory through the QT_QPA_PLATFORM_PLUGIN_PATH variable.
QT_QPA_PLATFORM_PLUGIN_PATH=path/to/plugins ./my_qt_app
or
export QT_QPA_PLATFORM_PLUGIN_PATH=path/to/plugins
./my_qt_app
The other option, which I prefer is to create a qt.conf file in the same directory as your executable. The contents of which would be:
[Paths]
Plugins=/path/to/plugins
More information regarding this can be found here and at using qt.conf
I tried to start my binary, compiled with Qt 5.7, on Ubuntu 16.04 LTS where Qt 5.5 is preinstalled. It didn't work.
At first, I inspected the binary itself with ldd as was suggested here, and satisfied all "not found" dependencies. Then this notorious This application failed to start because it could not find or load the Qt platform plugin "xcb" error was thrown.
How to resolve this in Linux
Firstly you should create platforms directory where your binary is, because it is the place where Qt looks for XCB library. Copy libqxcb.so there. I wonder why authors of other answers didn't mention this.
Then you may want to run your binary with QT_DEBUG_PLUGINS=1 environment variable set to check which dependencies of libqxcb.so are not satisfied. (You may also use ldd for this as suggested in the accepted answer).
The command output may look like this:
me#xerus:/media/sf_Qt/Package$ LD_LIBRARY_PATH=. QT_DEBUG_PLUGINS=1 ./Binary
QFactoryLoader::QFactoryLoader() checking directory path "/media/sf_Qt/Package/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/media/sf_Qt/Package/platforms/libqxcb.so"
Found metadata in lib /media/sf_Qt/Package/platforms/libqxcb.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"xcb"
]
},
"className": "QXcbIntegrationPlugin",
"debug": false,
"version": 329472
}
Got keys from plugin meta data ("xcb")
loaded library "/media/sf_Qt/Package/platforms/libqxcb.so"
QLibraryPrivate::loadPlugin failed on "/media/sf_Qt/Package/platforms/libqxcb.so" : "Cannot load library /media/sf_Qt/Package/platforms/libqxcb.so: (/usr/lib/x86_64-linux-gnu/libQt5DBus.so.5: version `Qt_5' not found (required by ./libQt5XcbQpa.so.5))"
This application failed to start because it could not find or load the Qt platform plugin "xcb"
in "".
Available platform plugins are: xcb.
Reinstalling the application may fix this problem.
Aborted (core dumped)
Note the failing libQt5DBus.so.5 library. Copy it to your libraries path, in my case it was the same directory where my binary is (hence LD_LIBRARY_PATH=.). Repeat this process until all dependencies are satisfied.
P.S. thanks to the author of this answer for QT_DEBUG_PLUGINS=1.
I tried the main parts of each answer, to no avail. What finally fixed it for me was to export the following environment variables:
LD_LIBRARY_PATH=/usr/local/lib:~/Qt/5.9.1/gcc_64/lib
QT_QPA_PLATFORM_PLUGIN_PATH=~/Qt/5.9.1/gcc_64/plugins/
Ubuntu 16.04 64bit.
I got the problem for apparently no reasons. The night before I watched a movie on my VideoLan instance, that night I would like to watch another one with VideoLan. VLC just didn't want to run because of the error into the question.
I google a bit and I found the solution it solved my problem: from now on, VLC is runnable just like before. The solution is this comand:
sudo ln -sf /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/ /usr/bin/
I am not able to explain what are its consequencies, but I know it creates some missing symbolic link.
Since version 5, Qt uses a platform abstraction system (QPA) to abstract from the underlying platform.
The implementation for each platform is provided by plugins. For X11 it is the XCB plugin. See Qt for X11 requirements for more information about the dependencies.
There might be many causes to this problem. The key is to use
export QT_DEBUG_PLUGINS=1
before you run your Qt application. Then, inspect the output, which will point you to the direction of the error. In my case it was:
Cannot load library /opt/nao/plugins/platforms/libqxcb.so: (/opt/nao/bin/../lib/libz.so.1: version `ZLIB_1.2.9' not found (required by /usr/lib/x86_64-linux-gnu/libpng16.so.16))
But that is solved in different threads. See for instance https://stackoverflow.com/a/50097275/2408964.
Probably this information will help. I was on Ubuntu 18.04 and when I tried to install Krita, using the ppa method, I got this error:
This application failed to start because it could not find or load the Qt platform plugin "xcb" in "".
Available platform plugins are: linuxfb, minimal, minimalegl, offscreen, wayland-egl, wayland, xcb.
Reinstalling the application may fix this problem.
Aborted
I tried all the solutions that I found in this thread and other webs without any success.
Finally, I found a post where the author mention that is possible to activate the debugging tool of qt5 using this simple command:
export QT_DEBUG_PLUGINS=1
After adding this command I run again krita I got the same error, however this time I knew the cause of that error.
libxcb-xinerama.so.0: cannot open shared object file: No such file or directory.
This error prevents to the "xcb" to load properly. So, the solution will be install the `libxcb-xinerama.so.0" right? However, when I run the command:
sudo apt install libxcb-xinerama
The lib was already installed. Now what Teo? Well, then I used an old trick :) Yeah, that one --reinstall
sudo apt install --reinstall libxcb-xinerama
TLDR: This last command solved my problem.
I ran into a very similar problem with the same error message. First, debug some by turning on the Qt Debug printer with the command line command:
export QT_DEBUG_PLUGINS=1
and rerun the application. For me this revealed the following:
"Cannot load library /home/.../miniconda3/lib/python3.7/site-packages/PyQt5/Qt/plugins/platforms/libqxcb.so: (libxkbcommon-x11.so.0: cannot open shared object file: No such file or directory)"
"Cannot load library /home/.../miniconda3/lib/python3.7/site-packages/PyQt5/Qt/plugins/platforms/libqxcb.so: (libxkbcommon-x11.so.0: cannot open shared object file: No such file or directory)"
Indeed, I was missing libxkbcommon-x11.so.0 and libxkbcommon-x11.so.0. Next, check your architecture using dpkg from the linux command line. (For me, the command "arch" gave a different and unhelpful result)
dpkg --print-architecture #result for me: amd64
I then googled "libxkbcommon-x11.so.0 ubuntu 18.04 amd64", and likewise for libxkbcommon-x11.so.0, which yields those packages on packages.ubuntu.com. That told me, in retrospect unsurprisingly, I'm missing packages called libxkbcommon-x11-0 and libxkbcommon0, and that installing those packages will include the needed files, but the dev versions will not. Then the solution:
sudo apt-get update
sudo apt-get install libxkbcommon0
sudo apt-get install libxkbcommon-x11-0
So, I spent about a day trying to figure out what was the issue; tried all the proposed solutions, but none of that worked like installing xcb libs or exporting Qt plugins folder. The solution that suggested to use QT_DEBUG_PLUGINS=1 to debug the issue didn't provide me a direct insight like in the answer - instead I was getting something about unresolved symbols within Qt5Core.
That gave me a hint, though: what if it's trying to use different files from different Qt installations? On my machine I had standard version installed in /home/username/Qt/ and some local builds within my project that I compiled by myself (I have other custom built kits as well in other locations). Whenever I tried to use any of the kits (installed by Qt maintenance tool or built by myself), I would get an "xcb error".
The solution was simple: provide the Qt path through CMAKE_PREFIX_PATH and not though Qt5_DIR as I did, and it solved the problem. Example:
cmake .. -DCMAKE_PREFIX_PATH=/home/username/Qt/5.11.1/gcc_64
I faced the same problem when after installing Viber. It had all required qt libraries in /opt/viber/plugins/.
I checked dependencies of /opt/viber/plugins/platforms/libqxcb.so and found missing dependencies. They were libxcb-render.so.0, libxcb-image.so.0, libxcb-icccm.so.4, libxcb-xkb.so.1
So I resolved my issue by installing missing packages with this libraries:
apt-get install libxcb-xkb1 libxcb-icccm4 libxcb-image0 libxcb-render-util0
I like the solution with qt.conf.
Put qt.conf near to the executable with next lines:
[Paths]
Prefix = /path/to/qtbase
And it works like a charm :^)
For a working example:
[Paths]
Prefix = /home/user/SDKS/Qt/5.6.2/5.6/gcc_64/
The documentation on this is here: https://doc.qt.io/qt-5/qt-conf.html
All you need to do is
pip uninstall PyQt5
and
conda install pyqt
Most of the problem of pyqt can be fixed by this simplest solution.
In my case, I needed to deploy two Qt apps on an Ubuntu virtualbox guest. One was command-line ("app"), the other GUI_based ("app_GUI").
I used "ldd app" to find out what the required libs are, and copied them
to the Ubuntu guest.
While the command-line executable "app" worked ok, the GUI-based executable crashed, giving
the "Failed to load platform plugin "xcb" error. I checked ldd for libxcb.so, but this too had no missing dependencies.
The problem seemed to be that while I did copy all the right libraries I accidentally had copied also libraries that were already present at the guest system.. meaning that (a) they were unnecessary to copy them in the first place and (b) worse, copying them produced incompatibilities between the install libraries.
Worse still, they were undetectable by ldd like I said..
The solution? Make sure that you copy libraries shown as missing by ldd and absolutely no extra libraries.
In my case missing header files were the reason libxcb was not built by Qt. Installing them according to https://wiki.qt.io/Building_Qt_5_from_Git#Linux.2FX11 resolved the issue:
yum install libxcb libxcb-devel xcb-util xcb-util-devel mesa-libGL-devel libxkbcommon-devel
Folks trying to get this started on Ubuntu 20.04 please try to run this and see if this solves the problem. This worked for me
sudo apt-get update -y
sudo apt-get install -y libxcb-xinerama0
I link all Qt stuff statically to the generic Linux builds of my open source projects. It makes life a bit easier. You just need to build static versions of Qt libraries first. Of course this cannot be applied to closed source software due to licensing issues. The deployment of Qt5 apps on Linux is currently a bit problematic, because Ubuntu 12.04, for example, doesn't have Qt5 libraries in the package repositories.
I had this problem, and on a hunch I removed the Qt Configs from my environment. I.e.,
rm -rf ~/.config/Qt*
Then I started qtcreator and it reconfigured itself with the existing state of the machine. It no longer remembered where my projects were, but that just meant I had to browse to them "for the first time" again.
But more importantly it built itself a coherent set of library paths, so I could rebuild and run my project executables again without the xcb or qxcb libraries going missing.
I faced the same situation, but on a Ubuntu 20.04 VM.
TL;DR: Check file permissions.
What I did:
I copied the Qt libs required to /usr/local/lib/x86_64-linux-gnu/ and added it to LD_LIBRARY_PATH
I copied the platforms folder from Qt to my application directory and added it to QT_PLUGIN_PATH
I ran ldd on the executable and in the offending libqxcb.so (ldd libqxcb.so), and it complains about some dependencies although ldconfig listed them as found.
linux-vdso.so.1 (0x00007ffee19af000)
libQt5XcbQpa.so.5 => not found
libfontconfig.so.1 => /lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007f7cb18fb000)
libfreetype.so.6 => /lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007f7cb183c000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f7cb1820000)
libQt5Gui.so.5 => /usr/local/lib/x86_64-linux-gnu/libQt5Gui.so.5 (0x00007f7cb0fd4000)
libQt5DBus.so.5 => not found
I used export QT_DEBUG_PLUGINS=1 for further info. It complains about missing files, although they are there.
What I found:
For some reason, when copying to the VM through the shared folder the files permissions were not the correct ones.
Thus, I ran: sudo chmod 775 * on the libs and voilĂ .
I solved the issue through this https://github.com/NVlabs/instant-ngp/discussions/300
pip uninstall opencv-python
pip install opencv-python-headless
This seems to have been a problem with the cv2 Python package and how it loops in Qt
sudo ln -sf /usr/lib/...."adapt-it"..../qt5/plugins/platforms/ /usr/bin/
It creates the symbolic link it's missed. Good for QT ! Good for VLC !!

Linux configuration ARToolKit, make error

I would like to compile ARToolKit source code on Linux, download the source code, and in accordance with the ARToolKit document, configuration GLUT, OpenGL, libjpeg other libraries.
Go to the ARToolKit directory and type ./Configer
Configer information image.
Enter the make command,The error occurs.
What are the causes of these errors? How can I solve? thanks.
according to your configuration screenshot you miss a gstreamer installation.
Please do:
sudo apt-get install libgstreamer0.10-dev
see here for more information: http://artoolkit.org/documentation/doku.php?id=8_Advanced_Topics:build_artoolkit
Let me know if that works for you
Edit:
Just saw that there are 3 more comments and that you already installed libgstreamer to fix the issue thanks to Michael O.

Lua cannot find LuaRocks-installed modules on Linux

I installed the luarocks package on Linux Mint, and afterwards installed a couple of rocks such as sudo luarocks install telescope, but when running a script via lua script.lua, require cannot find the module.
Meta: Doing this Q&A style, because while questions that answer this exist, none seem to be generically titled or easily findable, and I hope that I can help someone with this.
In this specific case, the problem was simply that on my distribution, the default Lua version installed was at the time of writing this 5.2, whereas the LuaRocks package was built for 5.1, meaning that Lua 5.2 could not find the rocks due to using different paths for modules.
The solution to the problem was downloading the LuaRocks source code from its github repository, and compiling it for 5.2
./configure --lua-version=5.2
make build
sudo make install
To make sure I can also install packages for LuaJIT, which as of the moment uses 5.1 libs, I have also executed the above lines with lua-version=5.1 beforehand (if I executed them after, the default luarocks command would point at the 5.1 build.
To build LuaRocks, you need liblua5.2-dev and/or liblua5.1-dev
The solution for me is this.
I try
eval "$(luarocks path)"
and it works.
Hope it works for others.

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