Installing CUDA driver for NVIDIA GPU in Ubuntu 20.04

First download CUDA driver from here: https://developer.nvidia.com/cuda-downloads

Choose operating system (Linux), architecture (x86_64), distribution (Ubuntu), Version (20.04), Installer type (deb (local)).

https://developer.nvidia.com/cuda-downloads?target_os=Linux&target_arch=x86_64&target_distro=Ubuntu&target_version=2004&target_type=deblocal

Then follow the instruction:

wget https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/cuda-ubuntu2004.pin
sudo mv cuda-ubuntu2004.pin /etc/apt/preferences.d/cuda-repository-pin-600
wget https://developer.download.nvidia.com/compute/cuda/11.2.2/local_installers/cuda-repo-ubuntu2004-11-2-local_11.2.2-460.32.03-1_amd64.deb
sudo dpkg -i cuda-repo-ubuntu2004-11-2-local_11.2.2-460.32.03-1_amd64.deb
sudo apt-key add /var/cuda-repo-ubuntu2004-11-2-local/7fa2af80.pub
sudo apt-get updatesudo apt-get -y install cuda

Redmine Installation Problems in Ubuntu 18.04.03

Problems encountered while installing Redmine 3.4.4 in Ubuntu 18.04.03

PROBLEM #1 Cannot Build SQLite3

# gem update
Updating installed gems
Updating sqlite3
Building native extensions. This could take a while...
ERROR: Error installing sqlite3:
ERROR: Failed to build gem native extension.

current directory: /var/lib/gems/2.5.0/gems/sqlite3-1.4.1/ext/sqlite3
/usr/bin/ruby2.5 -r ./siteconf20190813-10918-113tafq.rb extconf.rb
checking for sqlite3.h... no
sqlite3.h is missing. Try 'brew install sqlite3',
'yum install sqlite-devel' or 'apt-get install libsqlite3-dev'
and check your shared library search path (the
location where your sqlite3 shared library is located).
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.

Provided configuration options:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/usr/bin/$(RUBY_BASE_NAME)2.5
--with-sqlcipher
--without-sqlcipher
--with-sqlite3-config
--without-sqlite3-config
--with-pkg-config
--without-pkg-config
--with-sqlcipher
--without-sqlcipher
--with-sqlite3-dir
--without-sqlite3-dir
--with-sqlite3-include
--without-sqlite3-include=${sqlite3-dir}/include
--with-sqlite3-lib
--without-sqlite3-lib=${sqlite3-dir}/lib

To see why this extension failed to compile, please check the mkmf.log which can be found here:

/var/lib/gems/2.5.0/extensions/x86_64-linux/2.5.0/sqlite3-1.4.1/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /var/lib/gems/2.5.0/gems/sqlite3-1.4.1 for inspection.
Results logged to /var/lib/gems/2.5.0/extensions/x86_64-linux/2.5.0/sqlite3-1.4.1/gem_make.out
Updating web-console
ERROR: Error installing web-console:
Unresolved dependency found during sorting - activesupport (>= 4.2.0) (requested by rails-dom-testing-2.0.3)
Gems updated: sqlite3

SOLUTION: as suggested in the error message, just install libsqlite3-dev:

apt-get install libsqlite3-dev

PROBLEM #2: cannot update webconsole

# gem update
Updating installed gems
Updating web-console
ERROR: Error installing web-console:
Unresolved dependency found during sorting - activesupport (>= 4.2.0) (requested by rails-dom-testing-2.0.3)
Nothing to update

SOLUTION:
as in https://stackoverflow.com/questions/56084457/getting-error-when-installing-web-console

‘gem install -f web-console’

PROBLEM #3: Cannot bundle install

bundle install is needed to upgrade all gems to latest versions.

Problem:
> bundle install --without development test
Traceback (most recent call last):
1: from /usr/local/bin/bundle:23:in `<main>'
/usr/local/bin/bundle:23:in `load': cannot load such file -- /usr/share/rubygems-integration/all/gems/bundler-1.16.1/exe/bundle (LoadError)

Solution:

SOLUTION #1:

Ref: https://github.com/bundler/bundler/issues/6227
Just run:

gem update --system
gem uninstall bundler
gem install bundler
bundle install

this solution doesn’t not always work

SOLUTION #2: Use old bundler

https://www.redmine.org/issues/30353

gem install bundler -v 1.17.3 # Currently the latest bundler version < 2.0
bundle _1.17.3_ install