Refer to gulpjs/gulp#2065 @phated recommend upgrading usage of vinyl to 2.0 or 2.1 and to stop using gulp-util. I can see that your project is using gulp-util and thus an old vinyl that they says isn't compatible with gulp 4.0.0.
For further discussions I think it's better that you take it directly with the @gulpjs project since I don't know whats exactly is the problem.
Refer to gulpjs/gulp#2065 @phated recommend upgrading usage of vinyl to 2.0 or 2.1 and to stop using gulp-util. I can see that your project is using gulp-util and thus an old vinyl that they says isn't compatible with gulp 4.0.0.
For further discussions I think it's better that you take it directly with the @gulpjs project since I don't know whats exactly is the problem.