BlandCorporation's questions

I've little idea how to describe this issue, so would welcome edit suggestions.

Sometimes the mouse clicking location and the mouse pointer location are offset or misaligned in my installation of GNOME with Ubuntu 22.04 and X11. I see the effect in Firefox and in Nautilus, and currently the only solution I have is to reboot. I would welcome some understanding of the cause of the issue and perhaps a way to address it.

Here is a video illustrating some of what I'm seeing:

https://imgchest.com/p/dl7pqnnw8yo

In the video you can see a Firefox window open. I right-click on the web page to open a context menu, and then the misalignment of the mouse visible pointer and the mouse actual clicking location seems to start. As the visible pointer moves about on the right of the window, the actual clicking location seems to reset to the top-left corner of the window and is seen through the hover reactions of the different Firefox buttons at the top-left.

Previously I was able to set single windows to turn to negative colours using CompizConfig Settings Manager. One could enable an accessibility plugin called "Negative" to switch the window in focus to inverse colours. This is helpful for people with certain visual conditions and needs.

How might this be achieved on Ubuntu 20.04 with the MATE desktop environment?

My mum has a wee laptop that needs, when it boots up, to reverse-SSH connect itself to a server (so I can help out when needed).

I'm struggling to get the connection to persist when it is started by systemd.

In /reverse_SSH.sh I've got something like this:

#!/bin/bash
while true; do
    ssh -R 19123:localhost:22 [email protected]
    sleep 1000
done

In /etc/systemd/system/reverse_SSH.service I've got something like this:

[Unit]
Description=reverse-SSH

[Service]
Type=fork
ExecStart=/reverse_SSH.sh

[Install]
WantedBy=multi-user.target

When I run sudo systemctl start reverse_SSH, the SSH connection does appear to happen, and the MOTD of the server can be seen in the output of sudo systemctl status reverse_SSH, but the SSH connection doesn't seem to persist and I can't access the machine on the server with a command like ssh sonnyboy@localhost -p 19123.

What nonsense am I doing wrong? Thanks!

In Nautilus, one can use the search function to search for parts of filenames, e.g. ".mkv" or ".jpg".

Let's say I have a media directory filled with image files and video files all of different formats. How can I search using a GUI file browser for files that are, say, video files (so .ogg, .mkv, .mp4 and so on) or files suited to being opened by default by a video player application?

I need Ubuntu 16.04 LTS and I'm hoping to install Lutris on it. When I attempt to install it using a PPA package, the package lutris is not found. The procedure for attempting this is as follows:

sudo add-apt-repository ppa:lutris-team/lutris
sudo apt-get update
sudo apt-get install lutris

When I attempt to download a TAR of Lutris and then to run its Python executable bin/lutris I encounter the error ImportError: cannot import name '_gi' from 'gi', in spite of the fact that the Python module gi is already installed.

So how might Lutris be installed on 16.04?

I want to change the TrackPoint driver from libinput to Synaptics. I am using a ThinkPad X390 and I have tried the latest version of the libinput driver and I have tried to find out why the libinput driver is behaving in a way that makes the TrackPoint unpleasant for me and I now want to change back to Synaptics until libinput is developed further. I have verified that the TrackPoint seems to be running well on 16.04, which features the Synaptics driver.

How might this switch be done from libinput to Synaptics on Ubuntu 18.04 LTS?

I have already run the following:

sudo apt install xserver-xorg-input-synaptics-hwe-18.04 xserver-xorg-input-evdev-hwe-18.04
sudo apt remove xserver-xorg-input-libinput-hwe-18.04

I have a 2019 ThinkPad X390 with Windows 10 and want to install Ubuntu. I have always used Legacy Boot previously, not UEFI, and want to see how to have that option. In the UEFI-BIOS, I can see that the option to change UEFI/Legacy Boot from UEFI Only to `Legacy Only' is not selectable and beside it is written the text

Unselectable for Kernel DMA Protection

How can the option to change this be enabled?

I have an Nvidia 1070 system with Ubuntu 18.04, Nvidia driver 396.37, CUDA 9.0, and then TensorFlow and Keras running on it.

Having run sudo apt update, when I run sudo apt upgrade, I get the following:

$ sudo apt upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies.
 libglx-mesa0 : Depends: libglapi-mesa (= 18.0.5-0ubuntu0~18.04.1) but 18.2.8-0ubuntu0~18.04.2 is installed
                Breaks: libglx-mesa0:i386 (!= 18.0.5-0ubuntu0~18.04.1) but 18.2.8-0ubuntu0~18.04.2 is installed
 libglx-mesa0:i386 : Breaks: libglx-mesa0 (!= 18.2.8-0ubuntu0~18.04.2) but 18.0.5-0ubuntu0~18.04.1 is installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

When I attempt the suggested sudo apt --fix-broken install I see the following:

$ sudo apt --fix-broken installReading package lists... Done
Building dependency tree       
Reading state information... Done
Correcting dependencies... Done
The following packages were automatically installed and are no longer required:
  libllvm6.0 libllvm6.0:i386 x11proto-dri2-dev x11proto-gl-dev
Use 'sudo apt autoremove' to remove them.
The following additional packages will be installed:
  libglx-mesa0
The following packages will be upgraded:
  libglx-mesa0
1 to upgrade, 0 to newly install, 0 to remove and 256 not to upgrade.
155 not fully installed or removed.
Need to get 0 B/135 kB of archives.
After this operation, 9216 B of additional disk space will be used.
Do you want to continue? [Y/n] y
(Reading database ... 591832 files and directories currently installed.)
Preparing to unpack .../libglx-mesa0_18.2.8-0ubuntu0~18.04.2_amd64.deb ...
Unpacking libglx-mesa0:amd64 (18.2.8-0ubuntu0~18.04.2) over (18.0.5-0ubuntu0~18.04.1) ...
dpkg: error processing archive /var/cache/apt/archives/libglx-mesa0_18.2.8-0ubuntu0~18.04.2_amd64.deb (--unpack):
 trying to overwrite '/usr/lib/x86_64-linux-gnu/libGLX_indirect.so.0', which is also in package nvidia-396 396.37-0ubuntu1
Errors were encountered while processing:
 /var/cache/apt/archives/libglx-mesa0_18.2.8-0ubuntu0~18.04.2_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

Based on my investigating this, I am prompted by this and this, to run the following command:

sudo apt-get -o Dpkg::Options::="--force-overwrite" install --fix-broken

However, I really would rather not screw up my setup (as it was a challenge getting compatible versions of CUDA, TensorFlow, Keras etc. working at all) so would value thoughts on whether this is a safe approach.

EDIT: Following this suggestion by @Jos, I made a backup of /usr/lib/x86_64-linux-gnu/libGLX_indirect.so.0 and the proceeded with the --force-overwrite approach. Following this, the infrastructure of TensorFlow, Keras and so on all seems to be working fine.

$ sudo apt-get -o Dpkg::Options::="--force-overwrite" install --fix-broken
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Correcting dependencies... Done
The following packages were automatically installed and are no longer required:
  libllvm6.0 libllvm6.0:i386 x11proto-dri2-dev x11proto-gl-dev
Use 'sudo apt autoremove' to remove them.
The following additional packages will be installed:
  libglx-mesa0
The following packages will be upgraded:
  libglx-mesa0
1 to upgrade, 0 to newly install, 0 to remove and 256 not to upgrade.
155 not fully installed or removed.
Need to get 0 B/135 kB of archives.
After this operation, 9216 B of additional disk space will be used.
Do you want to continue? [Y/n] y
(Reading database ... 591832 files and directories currently installed.)
Preparing to unpack .../libglx-mesa0_18.2.8-0ubuntu0~18.04.2_amd64.deb ...
Unpacking libglx-mesa0:amd64 (18.2.8-0ubuntu0~18.04.2) over (18.0.5-0ubuntu0~18.04.1) ...
dpkg: warning: overriding problem because --force enabled:
dpkg: warning: trying to overwrite '/usr/lib/x86_64-linux-gnu/libGLX_indirect.so.0', which is also in package nvidia-396 396.37-0ubuntu1

I have loads of programs that require Qt4 and I need to install programs that require Qt5. When I try to install Qt5 things start off dodgy and then proceed to insanity. I request friendly guidance. It's probably easiest for you to look at the terminal output directly:

$ sudo apt update
Ign:1 http://linux.dropbox.com/ubuntu wily InRelease
Ign:2 http://repo.ubports.com xenial InRelease                                                                  
Hit:3 http://linux.dropbox.com/ubuntu wily Release                                                              
Hit:4 http://gb.archive.ubuntu.com/ubuntu xenial InRelease                                                      
Ign:5 http://repo.ubports.com xenial_-_mir26 InRelease                                                          
Hit:6 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu xenial InRelease                                           
Hit:8 http://gb.archive.ubuntu.com/ubuntu xenial-updates InRelease                                              
Hit:9 http://repo.ubports.com xenial Release                                                                    
Hit:10 http://security.ubuntu.com/ubuntu xenial-security InRelease                                              
Hit:11 http://gb.archive.ubuntu.com/ubuntu xenial-backports InRelease                                           
Hit:12 http://repo.ubports.com xenial_-_mir26 Release                                          
Hit:13 http://ppa.launchpad.net/maarten-baert/simplescreenrecorder/ubuntu xenial InRelease
Hit:14 https://repo.nordvpn.com/deb/nordvpn/debian stable InRelease          
Hit:15 http://ppa.launchpad.net/nextcloud-devs/client/ubuntu xenial InRelease
Hit:17 http://ppa.launchpad.net/numix/ppa/ubuntu xenial InRelease             
Hit:19 http://ppa.launchpad.net/otto-kesselgulasch/gimp/ubuntu xenial InRelease
Hit:20 http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu xenial InRelease
Hit:21 https://updates.signal.org/desktop/apt xenial InRelease
Hit:22 https://riot.im/packages/debian xenial InRelease
Reading package lists... Done 
Building dependency tree       
Reading state information... Done
23 packages can be upgraded. Run 'apt list --upgradable' to see them.

$ sudo apt install qt5-default
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies.
 protonmail-bridge : Depends: libqt5designer5 but it is not going to be installed
                     Depends: libqt5multimediawidgets5 but it is not going to be installed
 qt5-default : Depends: qtbase5-dev
               Depends: qtchooser (>= 55-gc9562a1-1~)
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

$ sudo apt install qtbase5-dev
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies.
 protonmail-bridge : Depends: qt5-default but it is not going to be installed
                     Depends: libqt5designer5 but it is not going to be installed
                     Depends: libqt5multimediawidgets5 but it is not going to be installed
 qtbase5-dev : Depends: libgles2-mesa-dev but it is not going to be installed or
                        libgles2-dev but it is not installable
               Depends: libqt5concurrent5 (= 5.9.5+dfsg-0ubports2) but it is not going to be installed
               Depends: qt5-qmake (= 5.9.5+dfsg-0ubports2)
               Depends: qtbase5-dev-tools (= 5.9.5+dfsg-0ubports2)
               Depends: qtchooser
               Recommends: libqt5opengl5-dev (= 5.9.5+dfsg-0ubports2)
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Correcting dependencies... Done
The following packages were automatically installed and are no longer required:
  audacity-data libflac++6v5 liblilv-0-0 libportsmf0v5 libqscintilla2-l10n libqt4-declarative libqt4-network
  libqt4-script libqt4-sql libqt4-sql-mysql libqt4-sql-sqlite libqt4-xml libqt4-xmlpatterns libqtcore4
  libqtdbus4 libqtgui4 libsbsms10 libserd-0-0 libsord-0-0 libsratom-0-0 libunibreak1 libvamp-hostsdk3v5
  libzlcore-data libzlcore0.13 libzltext-data libzltext0.13 linux-headers-4.15.0-42
  linux-headers-4.15.0-42-generic linux-image-4.15.0-42-generic linux-modules-4.15.0-42-generic
  linux-modules-extra-4.15.0-42-generic simplescreenrecorder-lib sqliteman-doc
Use 'sudo apt autoremove' to remove them.
The following packages will be REMOVED
  audacity fbreader libqscintilla2-12v5 libqt4-designer libqt4-opengl libqt4-svg libsuil-0-0 libzlui-qt4
  protonmail-bridge simplescreenrecorder sqliteman vidyodesktop
0 to upgrade, 0 to newly install, 12 to remove and 23 not to upgrade.
1 not fully installed or removed.
After this operation, 45.6 MB disk space will be freed.
Do you want to continue? [Y/n] n

The final suggestion of my attempt would remove some core things I need, so this is not an option. How might I proceed, kindly stranger?

On attempting to launch Jupyter on Python 3.7, I observe the following:

$ jupyter notebook
Traceback (most recent call last):
  File "/usr/local/bin/jupyter-notebook", line 11, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.7/dist-packages/jupyter_core/application.py", line 266, in launch_instance
    return super(JupyterApp, cls).launch_instance(argv=argv, **kwargs)
  File "/usr/local/lib/python3.7/dist-packages/traitlets/config/application.py", line 657, in launch_instance
    app.initialize(argv)
  File "<decorator-gen-7>", line 2, in initialize
  File "/usr/local/lib/python3.7/dist-packages/traitlets/config/application.py", line 87, in catch_config_error
    return method(app, *args, **kwargs)
  File "/usr/local/lib/python3.7/dist-packages/notebook/notebookapp.py", line 1629, in initialize
    self.init_webapp()
  File "/usr/local/lib/python3.7/dist-packages/notebook/notebookapp.py", line 1379, in init_webapp
    self.jinja_environment_options,
  File "/usr/local/lib/python3.7/dist-packages/notebook/notebookapp.py", line 158, in __init__
    default_url, settings_overrides, jinja_env_options)
  File "/usr/local/lib/python3.7/dist-packages/notebook/notebookapp.py", line 270, in init_settings
    nbextensions_path=jupyter_app.nbextensions_path,
  File "/usr/local/lib/python3.7/dist-packages/notebook/notebookapp.py", line 1066, in nbextensions_path
    from IPython.paths import get_ipython_dir
  File "/usr/local/lib/python3.7/dist-packages/IPython/__init__.py", line 54, in <module>
    from .core.application import Application
  File "/usr/local/lib/python3.7/dist-packages/IPython/core/application.py", line 25, in <module>
    from IPython.core import release, crashhandler
  File "/usr/local/lib/python3.7/dist-packages/IPython/core/crashhandler.py", line 27, in <module>
    from IPython.core import ultratb
  File "/usr/local/lib/python3.7/dist-packages/IPython/core/ultratb.py", line 119, in <module>
    from IPython.utils import path as util_path
  File "/usr/local/lib/python3.7/dist-packages/IPython/utils/path.py", line 17, in <module>
    from IPython.utils.process import system
  File "/usr/local/lib/python3.7/dist-packages/IPython/utils/process.py", line 19, in <module>
    from ._process_posix import system, getoutput, arg_split, check_pid
  File "/usr/local/lib/python3.7/dist-packages/IPython/utils/_process_posix.py", line 23, in <module>
    import pexpect
  File "/usr/lib/python3/dist-packages/pexpect/__init__.py", line 75, in <module>
    from .pty_spawn import spawn, spawnu
  File "/usr/lib/python3/dist-packages/pexpect/pty_spawn.py", line 15, in <module>
    from .spawnbase import SpawnBase
  File "/usr/lib/python3/dist-packages/pexpect/spawnbase.py", line 218
    def expect(self, pattern, timeout=-1, searchwindowsize=-1, async=False):
                                                                   ^
SyntaxError: invalid syntax

I've installed python3.7-distutils (which appears to feature pexpect) and I've reinstalled Jupyter using pip3, yet I still see this error. I've also uninstalled and reinstalled the following packages:

python3.7 python3.7-dev python3.7-distutils python3.7-tk

What should be done?

I see reference to this fix but, assuming it is a fix, don't know how to get it up and running on this 16.04 LTS install.

EDIT: On importing pexpect in Python 3.7, I get the same sort of thing:

>>> import pexpect
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3/dist-packages/pexpect/__init__.py", line 75, in <module>
    from .pty_spawn import spawn, spawnu
  File "/usr/lib/python3/dist-packages/pexpect/pty_spawn.py", line 15, in <module>
    from .spawnbase import SpawnBase
  File "/usr/lib/python3/dist-packages/pexpect/spawnbase.py", line 218
    def expect(self, pattern, timeout=-1, searchwindowsize=-1, async=False):
                                                                   ^
SyntaxError: invalid syntax

My computers have been freezing too much because of a lack of RAM. I need this to happen less. I am aware that the system in this high-RAM usage state is technically still solving the problem via SSD usage or whatnot, but I cannot wait hours for the system to resolve the problem. I am running up-to-date 16.04 and I require this version of Ubuntu.

Note that my computers are not particularly old, both are from within the last three years and have a minimum of 8 GB RAM. I suspect that this memory issue is arising from a larger preponderance of Electron apps.

I run indicator-sysmonitor which shows how much RAM memory is being used and can see that memory usage is clearly the problem because the freeze occurs when the memory usage is displayed at something like 97 % before things go bad.

So, the current solutions inbuilt in Ubuntu/GNU/Linux are not working for me.

• What solutions that might suit me better exist?

Right now I imagine creating a blacklist of programs (e.g. Firefox, Chromium, Signal, Riot) with a small program killing these blacklisted programs in order of their memory usage if the total system memory usage approaches 97%.

• Does such a solution exist?
• How might it be enabled on my systems?

EDIT: I have added swap details below:

$ swapon --summary
Filename                Type        Size    Used    Priority
/dev/sda5                               partition   12469244    0   -1
$ free -h
              total        used        free      shared  buff/cache   available
Mem:            11G        1.9G        5.8G        943M        3.9G        8.4G
Swap:           11G          0B         11G

EDIT: As some have suggested, this is absolutely nothing to do with limiting the memory process of a single process (as described here). This is about looking at the total memory usage and then progressively taking actions against a blacklist of programs as an urgent measure to stop the computer freezing up. A solution is presented below. Please answer if there is a better approach to this.

I wanna play my sweet sweet slow jams but I ain't got no track listing in my VLC indicator applet drop-down in Unity on 16.04! Friendos, in all of this green and blue planet, how might this me done?

EDIT: When I try using the speaker drop-down menu with Rhythmbox, I don't see a track listing, only controls. I need to see like a listing of maybe 6 or so tracks, like 3 just played and 3 upcoming, something like that.

In Ubuntu 16.04, if I double-click on an ISO file, Ubuntu gets the volume ID, then mounts that ISO at a directory at /media/$USER/ with the volume ID as the name of the directory. It does this without any request for root permissions.

I want to replicate this behavior in the terminal. I don't want to go first parsing the output of isoinfo -d -i data.iso, then granting root permissions to the user so that they then run mkdir in /media/ followed by running the mount command etc. I want to replicate what Ubuntu is actually doing and I want to replicate it without asking the user for root permissions.

How might this be done?

I'm trying to run a Flask application via HTTPS on Gunicorn.

Up to now I have been running it successfully via HTTP using a command like the following:

gunicorn --workers=4 "program.__main__:WSGI()" --bind=0.0.0.0:8080

Now I am trying to run it via HTTPS using a command like the following:

gunicorn --workers=4 "program.__main__:WSGI()" --bind=0.0.0.0:443 --certfile=fullchain.pem --keyfile=privkey.pem

When I run this as a normal user, I get output like the following:

[2018-08-13 21:26:28 +0000] [15170] [INFO] Starting gunicorn 19.9.0
[2018-08-13 21:26:28 +0000] [15170] [ERROR] Retrying in 1 second.
[2018-08-13 21:26:29 +0000] [15170] [ERROR] Retrying in 1 second.
[2018-08-13 21:26:30 +0000] [15170] [ERROR] Retrying in 1 second.
[2018-08-13 21:26:31 +0000] [15170] [ERROR] Retrying in 1 second.
[2018-08-13 21:26:32 +0000] [15170] [ERROR] Retrying in 1 second.
[2018-08-13 21:26:33 +0000] [15170] [ERROR] Can't connect to ('0.0.0.0', 443)

As root, it works, but I'm disinclined to run a web server as root. How should I run this securely?

In X11 I have many keyboard shortcuts that result in various pieces of text being typed into whatever application I'm using. A representative example is typing a timestamp when I press Ctrl+Alt+d. This is done by setting the following command as a keyboard shortcut:

bash -c "sleep 0.1; xvkbd -text $(date "+%Y-%m-%dT%H%MZ" --utc) 2>/dev/null"

These shortcuts are essential to me and I use them perhaps once every minute. How can the same functionality be achieved in Wayland?

I have VeraCrypt installed on a server and want to think about making it available to users on the server to make encrypted files in their home directories. What are the security vulnerabilities to think about?

For example, running VeraCrypt requires root permissions for it even to create a local file and I don't want users to be able to screw with a server system volume. I also don't want privilege escalations risks like those mentioned here.

Root permissions for VeraCrypt could be made available to users by adding the following to /etc/sudoers.tmp:

%veracrypt ALL=(root) NOPASSWD:/usr/bin/veracrypt

Can users use VeraCrypt without these privilege escalation risks and without being able to change the computer in any places other than their home directories?

I am new to Node, JavaScript etc. and want to try messing with the code of Signal. For this I need a specific version of Node. I did this (on Ubuntu 16.04) using the following procedure:

wget https://nodejs.org/dist/v8.2.1/node-v8.2.1-linux-x64.tar.gz
sudo mkdir -p /opt/nodejs
sudo tar -xvzf node-v8.2.1-linux-x64.tar.gz -C /opt/nodejs/
cd /opt/nodejs/
sudo mv node-v8.2.1-linux-x64 8.2.1
sudo ln -s 8.2.1 current
sudo ln -s /opt/nodejs/current/bin/node /bin/node
mode -v

I then installed NPM:

sudo apt install npm

I then started working through the setup steps for Signal:

sudo npm install --global yarn
sudo yarn install --frozen-lockfile
sudo yarn grunt

When I run this last command, I see that an incorrect version of Node is being used and then encounter an error:

yarn run v1.5.1
warning You are using Node "4.2.6" which is not supported and may encounter bugs or unexpected behavior. Yarn supports the following semver range: "^4.8.0 || ^5.7.0 || ^6.2.2 || >=8.0.0"
error An unexpected error occurred: "Couldn't find a package.json file in \"/opt/nodejs\"".
info If you think this is a bug, please open a bug report with the information provided in "/opt/nodejs/yarn-error.log".
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

What is going wrong?

When I try to import Beautifulsoup

import bs4

I keep getting the error

ImportError: No module named bs4

I have tried to address this by trying all of the following (individually and together) with Python 3 and have had no success. What's going wrong?

sudo pip3 install beautifulsoup4
sudo apt-get install python3-bs4

I installed an application using a command of the following form:

flatpak --user install -y --app --bundle "$DIR/Suphead.flatpak"

I uninstalled it using a command of the following form:

flatpak --user uninstall org.flatpaklinux.Suphead

However, after uninstall, I still see many files on the system associated with the application, files at all of the following sorts of directories:

~/.local/share/flatpak/repo/refs/remotes/org.flatpaklinux.Suphead-origin
~/.local/share/flatpak-linux/Suphead
~/.local/share/flatpak-linux/Suphead/drive_c
~/.var/app/org.flatpaklinux.Suphead

Should Flatpak not remove directories like these and their contents? Should I just do an rm -rf on them?

I'm trying to compile a program that makes use of OpenCL and CUDA and GPUs. I've attempted to install Nvidia drivers, CUDA, cuDNN, GCC and OpenCL on my Ubuntu 16.10 GTX 1070 machine and, for the most part, things seem to be working. However, I'm still unsure of how to set up OpenCL such that I can compile the program.

At a glance, I'm trying to compile oclvanitygen, which is an OpenCL program for generating Bitcoin wallets. I run into difficulties when I try to compile it.

>git clone https://github.com/samr7/vanitygen.git
>cd vanitygen
>gcc -o  oclvanitygen oclvanitygen.c -lOpenCL
/tmp/ccPaWgka.o: In function `main':
oclvanitygen.c:(.text+0x50c): undefined reference to `vg_exec_context_new_key'
oclvanitygen.c:(.text+0x529): undefined reference to `EC_KEY_get0_group'
oclvanitygen.c:(.text+0x53e): undefined reference to `EC_POINT_hex2point'
oclvanitygen.c:(.text+0x554): undefined reference to `EC_KEY_free'
oclvanitygen.c:(.text+0x815): undefined reference to `RAND_load_file'
oclvanitygen.c:(.text+0x894): undefined reference to `vg_regex_context_new'
oclvanitygen.c:(.text+0x8b8): undefined reference to `vg_prefix_context_new'
oclvanitygen.c:(.text+0x935): undefined reference to `vg_output_match_console'
oclvanitygen.c:(.text+0x947): undefined reference to `vg_output_timing_console'
oclvanitygen.c:(.text+0x9d4): undefined reference to `vg_context_add_patterns'
oclvanitygen.c:(.text+0xa28): undefined reference to `vg_read_file'
oclvanitygen.c:(.text+0xa9c): undefined reference to `vg_prefix_context_set_case_insensitive'
oclvanitygen.c:(.text+0xabb): undefined reference to `vg_context_add_patterns'
oclvanitygen.c:(.text+0xb37): undefined reference to `vg_read_password'
oclvanitygen.c:(.text+0xb86): undefined reference to `vg_check_password_complexity'
oclvanitygen.c:(.text+0xc33): undefined reference to `vg_ocl_context_new_from_devstr'
oclvanitygen.c:(.text+0xcdc): undefined reference to `vg_ocl_context_new'
oclvanitygen.c:(.text+0xd06): undefined reference to `vg_ocl_enumerate_devices'
oclvanitygen.c:(.text+0xd1c): undefined reference to `vg_context_start_threads'
oclvanitygen.c:(.text+0xd41): undefined reference to `vg_context_wait_for_completion'
oclvanitygen.c:(.text+0xd50): undefined reference to `vg_ocl_context_free'
collect2: error: ld returned 1 exit status

What is likely going wrong and how can I fix it?

The specific details of how I set up the system are listed below. I'm guessing that there are some steps I've done incorrectly with regards to letting the compiler have access to what it needs of OpenCL.

I installed Nvidia drivers.

sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt update
sudo apt install            \
    nvidia-367              \
    nvidia-prime            \
    nvidia-modprobe         \
    nvidia-opencl-dev

I installed CUDA.

sudo dpkg -i cuda-repo-ubuntu1604-8-0-local-ga2_8.0.61-1_amd64.deb
sudo apt-get update
sudo apt-get install cuda

This installed CUDA at directory /usr/local/cuda-8.0. I included directory /usr/local/cuda-8.0/bin in the PATH environment variable.

export PATH=/usr/local/cuda-8.0/bin${PATH:+:${PATH}}

I installed cuDNN.

tar -xvf cudnn-8.0-linux-x64-v5.1.tgz

The cuDNN archive contains the following:

cuda/include/cudnn.h
cuda/lib64/libcudnn.so
cuda/lib64/libcudnn.so.5
cuda/lib64/libcudnn.so.5.1.10
cuda/lib64/libcudnn_static.a

I copied some of these files to other directories because the internet told me to.

sudo cp cuda/include/cudnn.h /usr/local/cuda-8.0/include/
sudo cp cuda/lib64/* /usr/local/cuda-8.0/lib64/

I installed and changed to GCC 4.9 for CUDA.

sudo apt-get install gcc-4.9 g++-4.9

ln -fs /usr/bin/gcc-4.9 /usr/bin/gcc
ln -fs /usr/bin/g++-4.9 /usr/bin/g++

OpenCL is included with CUDA. I created a symbolic link to the Nvidia OpenCL headers at directory /usr/include.

sudo ln -s /usr/include/nvidia-375/CL /usr/include

I linked to the compiled OpenCL library file too:

sudo ln -s /usr/lib/x86_64-linux-gnu/libOpenCL.so.1 /usr/local/lib/libOpenCL.so