Configuration to run sassc on a single file in test subdir of libsass/sassc in libsass repo

gulpfile.js

//              _        __ _ _
//             | |      / _(_) |
//   __ _ _   _| |_ __ | |_ _| | ___
//  / _` | | | | | '_ \|  _| | |/ _ \
// | (_| | |_| | | |_) | | | | |  __/
//  \__, |\__,_|_| .__/|_| |_|_|\___|
//   __/ |       | |
//  |___/        |_|

var gulp         = require('gulp');
var run          = require('gulp-run');
var rename       = require("gulp-rename");

gulp.task('sassc', function () {
  gulp.src('test.scss')
    .pipe(run('../bin/sassc -s', {verbosity: 1}))
    .on('error', function (err) { this.end(); })
    .pipe(rename(function (path) { path.extname = ".css"; }))
    .pipe(gulp.dest('.'))
});

gulp.task('watch', function () {
    gulp.watch('test.scss', ['sassc']);
});

gulp.task('default', ['watch']);