Besides the mentioned side effects, Modafinil could in very rare cases cause SJS (Stevens-Johnson Syndrome – 5 cases per 1 million people). 
People with certain genetic predispositions can develop this condition which shows on your body as a rush. It can be triggered by several drugs (like cocaine, phenytoin, valproic, carbamazepine, lamotrigine, barbiturates, and some others), infections (herpes, influenza, hepatitis,..), but there are also genetic predispositions that can cause the SJS.
If you carry one of the following leukocytes, you should be careful: HLA-B*5801, HLA-B*1502, HLA-B*5801, HLA-B*44, HLA-A29<, HLA-B12, HLA-DR7, HLA-A2, HLA-B*5801, HLA-A*0206, HLA-DQB1*0601.
To make it easier for you, I couldn’t find any person who had issues with SJS.
Now, if any of the following side effects happen, then I do suggest calling a doctor:
- depression, anxiety, suicidal thoughts or actions;
- hallucinations, unusual thoughts or behavior, aggression, being more active or talkative than usual;
- chest pain, trouble breathing, uneven heartbeats; or
- the first sign of any skin rash, no matter how minor you think it might be.
My recommendation: If you decide you will try Modafinil, it’s good to have a friend or someone else around you. This is a precaution that doesn’t cost you anything (if you don’t have super weird friends – sorry) and brings an additional peace in your mind.
When I took Modafinil for the first time, I was, of course, thinking about SJS. But it’s such a rare thing and since I was very sick as a kid (and I got a lot of antibiotics), I would probably develop this earlier had I been so unlucky.
To sum this up, based on my research and the studies that I found, Modafinil is a safe smart-drug to take occasionally and probably also in the long term.
I would still suggest talking to your doctor before you try it out.