I've seen this before, give this a try:
Solution
To resolve this, follow the instructions below prior to running the gulp commands:
1. In the root directory of SCA using the command prompt window, go to ./node_modules/gulp-ttf2woff
2.
3. Run npm install ttf2woff@2.0.2
4.
5. Go to ./node_modules/gulp-ttf2eot
6.
7. Run npm install ttf2eot@2.0.0