example: https://github.com/ikuwow/query_ok/blob/master/.circleci/config.yml#L9
$ circleci build
====>> Spin up Environment
Build-agent version 0.0.5610-e7533b7 (2018-05-12T01:16:50+0000)
Starting container circleci/ruby:2.4.4
using image circleci/ruby@sha256:220868a4784846055941afb26926f81c7dec331f1c67385a29b0b61b458e2e72
Using build environment variables:
BASH_ENV=/tmp/.bash_env-localbuild-1526111429
CI=true
CIRCLECI=true
CIRCLE_BRANCH=master
CIRCLE_BUILD_NUM=
CIRCLE_JOB=build
CIRCLE_NODE_INDEX=0
CIRCLE_NODE_TOTAL=1
CIRCLE_REPOSITORY_URL=git@github.com:ikuwow/query_ok.git
CIRCLE_SHA1=278c6c954d455d248fd0f476cafa0812e321689e
CIRCLE_SHELL_ENV=/tmp/.bash_env-localbuild-1526111429
CIRCLE_WORKING_DIRECTORY=~/project
====>> Checkout code
#!/bin/sh
mkdir -p /home/circleci/project && cp -r /tmp/_circleci_local_build_repo/. /home/circleci/project
cp: cannot stat '/tmp/_circleci_local_build_repo/.': No such file or directory
Error: Exited with code 1
Step failed
Task failed