Git Assembla use project inside solution from different space

Question

I am newbie in git assembla so please explain in proper way :)
I have 2 spaces in my assembla account, one space is for my solution, one space is for a logger project i use in my solution.
The reason i use 2 spaces is because the logging project is shared with other users so they could also use it in their solutions.
So what i wanted to do ? i need to add the project in my solution.
Open visual studio, choose use existing item and load the project (it is already on my disk since i am the one who created and pushed for the first time).
Is this the proper way to do it ? And if so, now when i edit a file in my solution, and try to commit and push, there is error message:

error: failed to push some refs to 'git@git.assembla.com:XXXX.git'
hint: Updates were rejected because the tip of your current branch is behind
hint: its remote counterpart. Merge the remote changes (e.g. 'git pull')
hint: before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.
Done

What does this means ?
Thanks !

Answer 1

There are changes on your remote that are not local, you need to merge these changes into your local repo first. You can either do a git pull or got rebase to get the remote changes.

I suggest you do a pull first which will result in a merge commit.

Another way is to stash your current work and then reapply after pulling.