I hope this is the appropriate place to report this. I struggled with using the alias directive because I (incorrectly) assumed that it was relative to root since all other parts of my nginx configs are. This is not mentioned in the documentation, it'd be nice to see it there.

If I'm completely off base, please correct me. Below are examples of what did and didn't work for me.

#THIS IS WRONG

server {
root /var/www;

location /i/
{
alias /images/;
}
}

#THIS IS RIGHT

server {
root /var/www;

location /i/
{
alias /var/www/images/;
}
}