This isn't an issue in gnupg, and this isn't an issue in Ubuntu.
To generate a key, you need to have entropy. To get kernel entropy, you need to perform activity. There is no way to generate a key on a machine that doesn't have any entropy. Either generate entropy by generating disk activity, typing at the keyboard and moving the mouse, or generate your keys on a machine that _does_ have some entropy. Alternatively, you may use a hardware entropy gathering device.
This isn't an issue in gnupg, and this isn't an issue in Ubuntu.
To generate a key, you need to have entropy. To get kernel entropy, you need to perform activity. There is no way to generate a key on a machine that doesn't have any entropy. Either generate entropy by generating disk activity, typing at the keyboard and moving the mouse, or generate your keys on a machine that _does_ have some entropy. Alternatively, you may use a hardware entropy gathering device.