message: chore(build): mark sourcemap external
diff: @@ -173,7 +173,7 @@ module.exports = {
  // Avoids generating `.js` from interface-only `.ts` files
  .pipe(filter(file => stripComments(file.contents.toString(), { sourceType: 'module' }).replace(/\s/g, '')))
  .on('error', log)
  - .pipe(sourcemaps.write())
  + .pipe(sourcemaps.write('.'))
  .pipe(gulp.dest(config.jsDestDir))
  );
  },
  