Error: "no writecb in Transform class"

[issander]

The error "no writecb in Transform class" is being thrown seemingly at random by the following task:

gulp.task('debug', function () {
    gulp.src('www/beheer/_lib/css/style.less')
        .pipe(plumber(function(error){
            gutil.log(gutil.colors.red(error.message));
            gutil.beep();
        }))
        .pipe(less())
        .pipe(gulp.dest('www/_lib/dist'));
});

After some searching I found the following issue that suggested that this particular error is caused by calling the callback function multiple times: geopipes/elasticsearch-backend#1

After placing some console.log lines in the gulp-less code it seems that the following part is to blame:

cb(null, file);

(index.js - line 68 - version 1.3.7)

In my case this callback is being called three times, the later two producing the error.

[issander]

Some further testing revealed that the callback that is passed to less.render is being called multiple times (with err being false).

Calling less.render with a promise rather than a callback seems to fix the problem.

[stephenlacy]

Please update to the newest version and confirm that these commits fixed your issue: #113

[issander]

Thanks @stevelacy , I have just tested v2.0.1 that includes these commits and the issue has indeed been fixed.

[jbcpollak]

We seem to be getting this same error with v3.0.1, is that possible?

[yocontra]

@jbcpollak Wipe node modules and reinstall maybe?

[jbcpollak]

I guess we are seeing a separate bug with similar symptoms. It seems to be caused by the use of the CSS3 /deep/ feature.

It looks like gulp-less depends on less ^2.1.1 and support for /deep/ was added in less 2.4.0.

less/less.js#2023

When we removed /deep/, the problem went away. Any chance an updated gulp-less could be released to depend on the newest less?

[yocontra]

@jbcpollak done

[yocontra]

Also you can just npm update, we use the range ^2.1.0 which includes 2.4.0

[jklmli]

Seeing this issue with gulp-autoprefixer on 3.0.2.

[yocontra]

@jiaweihli So open it on gulp-autoprefixer 🌴

[wrightling]

I get this same error with gulp-less 3.0.3, but not if I go back to 3.0.2. I'm not super familiar with the npm module open source world - what can I provide that is useful in terms of information?

2.0.0-p247 in customer_commerce/ on develop-ever
› npm list gulp-less
npm WARN unmet dependency /Users/wwright/Dev/web/frontend/customer_commerce/node_modules/gulp-eslint requires eslint@'^0.18.0' but will load
npm WARN unmet dependency /Users/wwright/Dev/web/frontend/customer_commerce/node_modules/eslint,
npm WARN unmet dependency which is version 0.19.0
customer-commerce@0.0.1 /Users/wwright/Dev/web/frontend/customer_commerce
└── gulp-less@3.0.3


2.0.0-p247 in customer_commerce/ on develop-ever
› gulp less
[12:38:24] Using gulpfile ~/Dev/web/frontend/customer_commerce/gulpfile.js
[12:38:24] Starting 'less'...
[12:38:27] [less] [Error: no writecb in Transform class]

Obviously I can open a new ticket, as this one is closed, but thought someone here might see a notification and already know why I'm seeing this and why it's not really an issue :P

[yocontra]

This is a weird thing that pops up sometimes where npm fails to install a dependency correctly (I think readable-stream). rm -rf node_modules && npm install to make things work correctly when npm shits the bed.

[AnatolyRugalev]

I had this issue when used old version of nodejs (0.10). Resolved with upgrading it to 0.12

[mark-williams]

Upgrading node did the trick for me too.

[sbhaktha]

I am seeing this issue! Using

    "gulp": "3.9.1",
    "gulp-less": "3.0.5",

Any ideas? Thanks!

[brettwhiteman]

Same here @sbhaktha

[brettwhiteman]

Ok updating nodejs fixed it

[vlaim]

I got this problem after updating to gulp 4 🤔

[wmai]

I got this problem after updating to gulp 4
- vlaim

Me too.

[flakfire]

I was able to fix this by re-installing Ruby with devkit and through the ruby command prompt run gem install slim after 'npm rebuild'. For some reason, this fixed it for me and was able to properly build.