When a user specifies a project but fails to specify a hash sign it leads to a mildly confusing error.
For example it says (for python instead of #python)
- Error parsing field "Reviewers": The objects you have listed include objects which do not exist (python).
This can lead to user confusion: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=201210
While there is still some confusion when a user and project exist that have the same name, it is worthwhile for arcanist to be more expressive in this case: perhaps something like:
- Error parsing field "Reviewers": The objects you have listed include objects which do not exist (python). Other similar objects include #python or python-foobar