Gulp failed with AssertionError

[ericluwj]

Using the current package.json dependency setting "gulp": ">=3.9.0",version 4.0.0 of gulp-cli is automatically installed.
Setting should be set such that only the version 3 of gulp-cli is installed instead.

Error obtained with gulp v4:

yarn build v0.24.6
$ gulp
assert.js:42
  throw new errors.AssertionError({
  ^

AssertionError [ERR_ASSERTION]: Task function must be specified
    at Gulp.set [as _setTask] (/Users/ericluwj/Projects/neb.js/node_modules/undertaker/lib/set-task.js:10:3)
    at Gulp.task (/Users/ericluwj/Projects/neb.js/node_modules/undertaker/lib/task.js:13:8)
    at Object.<anonymous> (/Users/ericluwj/Projects/neb.js/gulpfile.js:71:6)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at execute (/Users/ericluwj/Projects/neb.js/node_modules/gulp-cli/lib/versioned/^4.0.0/index.js:36:18)
    at Liftoff.handleArguments (/Users/ericluwj/Projects/neb.js/node_modules/gulp-cli/index.js:175:63)
    at Liftoff.execute (/Users/ericluwj/Projects/neb.js/node_modules/liftoff/index.js:203:12)
    at module.exports (/Users/ericluwj/Projects/neb.js/node_modules/flagged-respawn/index.js:51:3)
    at Liftoff.<anonymous> (/Users/ericluwj/Projects/neb.js/node_modules/liftoff/index.js:195:5)
    at /Users/ericluwj/Projects/neb.js/node_modules/liftoff/index.js:165:9
error Command failed with exit code 1.

[sunnypandas]

Hi, I have this problem, too. Do you resolved it? Thanks. @ericluwj

[ericluwj]

Try ./node_modules/.bin/gulp instead.

[sunnypandas]

Maybe we should use gulp V3 instead of V4. Thank you. @ericluwj

[mohindergupta]

I had the same problem and resolved it as follows
As per the instructions in readme doc, ran the command "npm install gulp -g" as mentioned in step 2 when i was trying to host marbles locally. This gave me the same error as discussed above.

2. To fix it, I removed the gulp completely from global and local directory by using the commands below. Ran both these commands to make sure gulp is removed locally and globally.
   npm rm gulp -g --save
   npm rm gulp --save (probably this is not needed, but i did it)

3. Installed gulp using following
   npm install gulp@3.9.1 -g --save
   npm install gulp@3.9.1 --save (probably this is not needed, but i did it)

After step 3, make sure you have both CLI and Local version as 3.9.1. If Local version is higher, then also I had the problem. I hope this helps.

[ivanlopezmolina]

I had the same problem and resolved it as follows
As per the instructions in readme doc, ran the command "npm install gulp -g" as mentioned in step 2 when i was trying to host marbles locally. This gave me the same error as discussed above.

1. To fix it, I removed the gulp completely from global and local directory by using the commands below. Ran both these commands to make sure gulp is removed locally and globally.
   npm rm gulp -g --save
   npm rm gulp --save (probably this is not needed, but i did it)
2. Installed gulp using following
   npm install gulp@3.9.1 -g --save
   npm install gulp@3.9.1 --save (probably this is not needed, but i did it)

After step 3, make sure you have both CLI and Local version as 3.9.1. If Local version is higher, then also I had the problem. I hope this helps.

yes last both installation are needed, thank you!

[alediez2048]

Thank you so much man, this solved my issue

[Sarah86]

yaaayyy!!! it had to be exactly this steps

[aastharawat]

v3 is deprecated. Here you are using the latest version but older code.
With v4,
replace gulp.watch('./sass/.sass', ['sass']) with gulp.watch('./sass/.sass', gulp.series('sass')).