Pipelines doesn't find SSH key in the default location as expected

From feedback on the https://confluence.atlassian.com/display/BITBUCKET/Use+SSH+keys+in+Bitbucket+Pipelines page

"I had to specify the key file being used (pipelines defaults to /opt/atlassian/pipelines/agent/data/id_rsa):

ssh -i ~/.ssh/id_rsa <user>@<host> 'echo "connected to hostname as $USER"'

wanted to report in case other people were having similar issues"