gulp-less minor dependency on less introduce : Source map bug introduced in less 2.7.0

[mlardy]

Hi

I'm stucked with a less bug :
_ Error in plugin 'gulp-less'
Message:
Invalid mapping: {"generated":{"line":190,"column":2},"source":".../bootstrap/less/print.less","original":{"line":1,"column":null},"name":null} in file undefined line no. undefined
Details:
lineNumber: undefined
fileName: undefined_

I think that you should not reference minor version changes in your package.json for less dependency.

If there are some bugs in dependencies like this one less/less.js#2896 we can't use a previous minor version of gulp-less with a previous less minor version.

You should probably release a gulp-less 3.1.x to point to a less ~2.6.x and upgrade minor of gulp-less when a less minor is released.

[leighgordy]

I'm having the same issue. Your plugin is pulling the latest less 2.7.0 which is currently broken. Changing your project so that it references 2.6.1 will bypass the issue.

[leighgordy]

Commenting out reference to gulp-source maps in the gulp script is the quickest way to bypass the 2.7.0 issue. e.g. pipe(sourcemaps.init()) pipe(sourcemaps.write('./')).

[felixfbecker]

The best way would be if gulp-less had the option to pass a custom reference to the less module, like gulp-typescript allows it. That way we could all easily revert to less@2.6
Example:

const gulpLess = require('gulp-less')
const less = require('less')

gulp.src('app.less')
  .pipe(gulpLess({less, paths: [__dirname + '/node_modules']}))
  .pipe(gulp.dest('build'))

[oBusk]

We would really like to be able to pass less as an option to have better control over which version to use.

const gulpLess = require('gulp-less');
const less = require('less');

gulp.src('app.less')
    .pipe(gulpLess({
        less: less
    });
    .pipe(gulp.dest('build'));

Similiar to how gulp-typescript does it.

However i guess it would be more correct and work even smoother if less was added as a peer dependency?

---

For anyone having this problem now do a npm install, npm shrinkwrap --dev and then modify the shrinkwrap version of "less" to be 2.6.1.

...
"less": {
          "version": "2.6.1",
          "from": "less@>=2.6.1 <2.7.0",
          "resolved": "https://registry.npmjs.org/less/-/less-2.6.1.tgz",
          "dependencies": {
...

Then do a clean install

[davetheflashguy]

Ran into this today, I too ended up doing what @leighgordy suggested.

[lucknerjb]

^ Ditto! Thanks @oBusk

[oBusk]

This should have been fixed with a 2.7.1 version of less. Doing an npm install/update should fix this problem. gulp-less would still benefit greatly from an ability to use a specific version of less.

[johnkors]

Related?

[15:42:00][Step 6/6] [15:42:00] Starting 'boostrapLess'...
[15:42:00][Step 6/6] [15:42:00] Starting 'less'...
[15:42:01][Step 6/6] [15:42:01] Invalid mapping: {"generated":{"line":1289,"column":2},"source":"Content/Styles/Libs/Bootstrap-3.3.6/type.less","original":{"line":1,"column":null},"name":null} in file undefined line no. undefined
[15:42:01][Step 6/6] [15:42:01] Finished 'boostrapLess' after 1.56 s
[15:42:02][Step 6/6] [15:42:02] Finished 'less' after 2.04 s

[davetheflashguy]

Yup @johnkors , I had the same issues yesterday with boostrap