Correction. To make the launcher work every time, the following command has to be used to start the launcher:
rm ~/.minecraft/webcache2/Default/Preferences ; minecraft
What is going on? This bug has been there for months.
Running the following bash command as the non root user that runs minecraft solved the issue for me:
rm ~/.minecraft/webcache2/Default/Preferences
Then after that running minecraft again and this time it works.
Correction. To make the launcher work every time, the following command has to be used to start the launcher:
rm ~/.minecraft/webcache2/Default/Preferences ; minecraft
What is going on? This bug has been there for months.