The actual gulp-sass v2 requires node-sass v3 and when tried to install the binary file is not there, so it gets the node-sass source code and compiles with node-gyp causing slow npm install time, this is solved using the latest gulp-sass version so it gets node-sass v4 and there is a binary working, so it doesn't need to compile all the source code.
The actual gulp-sass v2 requires node-sass v3 and when tried to install the binary file is not there, so it gets the node-sass source code and compiles with node-gyp causing slow npm install time, this is solved using the latest gulp-sass version so it gets node-sass v4 and there is a binary working, so it doesn't need to compile all the source code.