Unable to self-update composer?

Question

I am trying to update composer with no luck!

What I have tried:

$ composer self-update

[InvalidArgumentException]

Answer 1

Install the latest version:

Remove your current composer version, for example ubuntu/debian:

sudo apt-get remove composer

Now, head to https://getcomposer.org/download/ and paste the script in your command line. This ensures that you get the latest version of composer (as time of writing: v2.0.7).

Like this:

php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
php -r "if (hash_file('sha384', 'composer-setup.php') === 'c31c1e292ad7be5f49291169c0ac8f683499effffdcfd4e42232982d0fd193004208a58ff6f353fde0012d35fdd72bc394') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"
sudo php composer-setup.php --install-dir=/usr/local/bin --filename=composer
php -r "unlink('composer-setup.php');"

after some time passed, you can update and no need to use sudo prefix:

composer self-update