(internetKeychainItemForServer:withUsername:path:port:protocol:) - The specified item could not be found in the keychain.

[swathi konakondla]

getting this error when pushing branch from source tree to bitbucket in mac

[Tyler B [Atlassian]]

As this is the first thing that comes up on Google when searching this error, I wanted to add the answer I found that worked when I stumbled upon this issue.

http://stackoverflow.com/questions/20217389/sourcetree-cant-push-to-bitbucket

In short: I didnt have write access to the repo.

[Ben White]

I was getting this because the case of the username I entered was not the same as the case of the username in the URL/path. e.g. I would type username, but the repo url was https://Username@server.com:8443/path/project.git 

[KieranA]

Hi Swathi,

This could be the same reason as from this post: https://answers.atlassian.com/questions/125892/submodule-with-different-user-fails-to-clone-push-with-sourcetree

In short, it might be because you're using HTTPS authentication and not specifying your username in the URL. Have a read and see if it helps.

Cheers