Upgrading node and yarn


You are getting the following error when trying to use yarn:


Upgrade yarn

Which should give the updated yarn version:

Upgrade node version with the correct version from above (ie 10.0.0)

And then the needed versions would have been installed:

Find the current AMI image (i.e. Ubuntu 16.04) in AWS using command line

If you would like to programatically find the current image of a specific distribution in AWS for your region, with the use of the aws cli, use the following (in this example looking for Ubuntu 16.04).

Or for 18.04

This is from the examples in the documentation here: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/finding-an-ami.html

Raspberry, Ubuntu and Megatools

To install megtools (command line utilities for Mega.nz), in your raspberry with ubuntu installed follow the steps below (thanks to the instructions from here: https://www.instructables.com/id/Descarga-archivos-de-Mega-con-Raspberry-Pi/)

  • Install the necessary packages

You may also need to add some additional packages if there is an error about the documentation.

  • Get the latest source code from https://megatools.megous.com
  • Compile and install them
  • Add your Mega account credentials in ~/.megarc like:
  • use the mega tools commands (megacopy, megals, megaget etc.

Erlang and Elixir with asdf in Raspberry 4 with Ubuntu 20.04

To install the latest/current versions of erlang (23.0.2) and elixir (1.10.3), follow the instructions below:

Install asdf ( full instructions https://asdf-vm.com/#/core-manage-asdf-vm):

Add the following two lines in your ~/.bashrc file:

Reload/Source your bash file with

Install the erlang plugin

If you get the following warnings:

Install the missing packages:

Install latest erlang version:

Set it up globally (if you want):

Add elixir plugin:

Install latest elixir version (1.10.3):

Set it up globally:

Finally you can also install the latest Phoenix version (1.5.3):

Cannot login to MariaDB server with root account


You are trying to login to MariaDB with the root user, but even after resetting the password, it is still not possible to login.


It seems that certain MariaDB packages that come with Linux distributions use the unix_socket as the authentication method.

MariaDB [mysql]> SELECT user, host, plugin FROM user WHERE user='root';
| user | host      | plugin      |
| root | localhost | unix_socket |
1 row in set (0.00 sec)

Change the plugin as described here (https://stackoverflow.com/a/43424234) with the following:

MariaDB [mysql]> UPDATE mysql.user SET plugin = '' WHERE user = 'root';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

Errors were encountered while processing: linux-image-3.13.0-128-generic


You are trying to install/remove a package but you always get an error message about linux message as above:


Try the following:

failed to execute ‘/lib/udev/socket:@/org/freedesktop/hal/udev_event’ ‘socket:@/org/freedesktop/hal/udev_event’


Looking at your /var/log/syslog you see entries every few seconds like the following:


Seems that hal is not used in newer Ubuntu versions, so you can remove it:

Taken from the answer here