在本地用户提示符，而不是根用户提示符中键入

sudo -u postgres createuser <local username>

输入本地用户密码。

然后输入前面的命令，生成“角色‘username’不存在”。

以上步骤为我解决了问题。 如果没有，请发送终端消息进行以上步骤。

对于Postgres 9.5版本，使用以下命令:

psql -h localhost -U postgres

希望这能有所帮助。

这对我来说很管用:

psql -h localhost -U postgres

遵循以下步骤，它将为你工作:

run msfconsole type db_console some information will be shown to you chose the information who tell you to make: db_connect user:pass@host:port.../database sorry I don't remember it but it's like this one then replace the user and the password and the host and the database with the information included in the database.yml in the emplacement: /usr/share/metasploit-framework/config you will see. rebuilding the model cache in the background. Type apt-get update && apt-get upgrade after the update restart the terminal and lunch msfconsole and it works you can check that by typing in msfconsole: msf>db_status you will see that it's connected.

对于使用docker并正确遵循官方文档说明的用户，如果仍然遇到此问题，请重新启动窗口并重试。

sudo -u postgres createuser --superuser $USER

sudo -u postgres createdb $USER

这绝对适合你。