nightcrawler-

# This is a skeleton for testing models including examples of validations, callbacks,
# scopes, instance & class methods, associations, and more.
# Pick and choose what you want, as all models don't NEED to be tested at this depth.
#
# I'm always eager to hear new tips & suggestions as I'm still new to testing,
# so if you have any, please share!
#
# @kyletcarlson
#
# This skeleton also assumes you're using the following gems: 

nightcrawler-

# http://webapps.stackexchange.com/questions/39587/view-estimated-size-of-github-repository-before-cloning
# tested on macOS
echo https://github.com/torvalds/linux.git | perl -ne 'print $1 if m!([^/]+/[^/]+?)(?:\.git)?$!' | xargs -I{} curl -s -k https://api.github.com/repos/'{}' | grep size

# output: 
# "size": 1746294,

nightcrawler-

psql: FATAL: Peer authentication failed for user “postgres” (or any user)

The connection failed because by default psql connects over UNIX sockets using peer authentication, that requires the current UNIX user to have the same user name as psql. So you will have to create the UNIX user postgres and then login as postgres or use sudo -u postgres psql database-name for accessing the database (and psql should not ask for a password).

If you cannot or do not want to create the UNIX user, like if you just want to connect to your database for ad hoc queries, forcing a socket connection using psql --host=localhost --dbname=database-name --username=postgres (as pointed out by @meyerson answer) will solve your immediate problem.

But if you intend to force password authentication over Unix sockets instead of the peer method, try changing the following pg_hba.conf* line:

from