gulp file is apparently not working

[jucajuca]

I get the following errror:

AssertionError [ERR_ASSERTION]: Task function must be specified
at Gulp.set [as _setTask] (/mnt/FILES/CODE/WP/html5blank/node_modules/undertaker/lib/set-task.js:10:3)
at Gulp.task (/mnt/FILES/CODE/WP/html5blank/node_modules/undertaker/lib/task.js:13:8)
at Object. (/mnt/FILES/CODE/WP/html5blank/gulpfile.js:86:6)
at Module._compile (internal/modules/cjs/loader.js:999:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)
at Module.load (internal/modules/cjs/loader.js:863:32)
at Function.Module._load (internal/modules/cjs/loader.js:708:14)
at Module.require (internal/modules/cjs/loader.js:887:19)
at require (internal/modules/cjs/helpers.js:74:18)
at requireOrImport (/usr/lib/node_modules/gulp-cli/lib/shared/require-or-import.js:19:11) {
generatedMessage: false,
code: 'ERR_ASSERTION',
actual: false,
expected: true,
operator: '=='
}