I'm running my vagrant provisioning with a *bootstrap.sh* script. The script runs fine except for one line:

```
echo "source /root/.venvburrito/startup.sh" >> ~/.profile

```

This line fails. I don't get any output about it, but when I do `vagrant ssh` and check the `~/.profile` file I can see that `source /root/.venvburrito/startup.sh` is not appended to the file. 

How can I append `source /root/.venvburrito/startup.sh` to the file so that command is sourced every time I do `vagrant ssh`?