Gulp build fails - Error in plugin "gulp-less"

[j055]

Bug Report

Gulp build fails at 'Building compressed CSS'

Steps to reproduce

gulp build

Expected result

Complete without errors

Actual result

D:\source\repos\app\semantic>gulp build
[13:54:26] Using gulpfile D:\source\repos\app\semantic\gulpfile.js
[13:54:26] Starting 'build'...
Building Semantic
[13:54:26] Starting 'build-css'...
[13:54:26] Starting 'Building uncompressed CSS'...
[13:54:26] Starting 'Building compressed CSS'...
Potentially unhandled rejection [2] Error: Error in plugin "gulp-less"
Message:
    Unrecognised input in file D:\source\repos\app\semantic\src\themes\default\globals\colors.less line no. 492
Details:
    type: Parse
    filename: D:\source\repos\app\semantic\src\themes\default\globals\colors.less
    index: 18389
    line: 492
    callLine: NaN
    callExtract: undefined
    column: 0
    extract: ,@formStates: {,  @error: {
    lineNumber: 492
    fileName: D:\source\repos\app\semantic\src\themes\default\globals\colors.less

    at DestroyableTransform.errorHandler (D:\source\repos\app\semantic\tasks\config\tasks.js:124:19)
    at DestroyableTransform.emit (events.js:187:15)
    at DestroyableTransform.EventEmitter.emit (domain.js:441:20)
    at onwriteError (D:\source\repos\app\node_modules\through2\node_modules\readable-stream\lib\_stream_writable.js:449:12)
    at onwrite (D:\source\repos\app\node_modules\through2\node_modules\readable-stream\lib\_stream_writable.js:470:11)
    at WritableState.onwrite (D:\source\repos\app\node_modules\through2\node_modules\readable-stream\lib\_stream_writable.js:180:5)
    at DestroyableTransform.afterTransform (D:\source\repos\app\node_modules\through2\node_modules\readable-stream\lib\_stream_transform.js:93:3)
    at D:\source\repos\app\node_modules\gulp-less\index.js:58:14
    at tryCatchReject (D:\source\repos\app\node_modules\when\lib\makePromise.js:845:30)
    at runContinuation1 (D:\source\repos\app\node_modules\when\lib\makePromise.js:804:4)
Potentially unhandled rejection [4] Error: Error in plugin "gulp-less"
Message:
    Unrecognised input in file D:\source\repos\app\semantic\src\themes\default\globals\colors.less line no. 492
Details:
    type: Parse
    filename: D:\source\repos\app\semantic\src\themes\default\globals\colors.less
    index: 18389
    line: 492
    callLine: NaN
    callExtract: undefined
    column: 0
    extract: ,@formStates: {,  @error: {
    lineNumber: 492
    fileName: D:\source\repos\app\semantic\src\themes\default\globals\colors.less

    at DestroyableTransform.errorHandler (D:\source\repos\app\semantic\tasks\config\tasks.js:124:19)
    at DestroyableTransform.emit (events.js:187:15)
    at DestroyableTransform.EventEmitter.emit (domain.js:441:20)
    at onwriteError (D:\source\repos\app\node_modules\through2\node_modules\readable-stream\lib\_stream_writable.js:449:12)
    at onwrite (D:\source\repos\app\node_modules\through2\node_modules\readable-stream\lib\_stream_writable.js:470:11)
    at WritableState.onwrite (D:\source\repos\app\node_modules\through2\node_modules\readable-stream\lib\_stream_writable.js:180:5)
    at DestroyableTransform.afterTransform (D:\source\repos\app\node_modules\through2\node_modules\readable-stream\lib\_stream_transform.js:93:3)
    at D:\source\repos\app\node_modules\gulp-less\index.js:58:14
    at tryCatchReject (D:\source\repos\app\node_modules\when\lib\makePromise.js:845:30)
    at runContinuation1 (D:\source\repos\app\node_modules\when\lib\makePromise.js:804:4)
[13:54:26] The following tasks did not complete: build, build-css, <series>, <series>, Building uncompressed CSS, Building compressed CSS
[13:54:26] Did you forget to signal async completion?

Testcase

Screenshot (if possible)

Version

2.8.4

[lubber-de]

Does npx gulp build work?

[lubber-de]

You seem to have changed either the colors.less file or you have installed an old vesion of LESS

[j055]

npx gulp build gives the same result

[j055]

It's a new file because I've upgraded from semantic-ui v2.4.2

[j055]

package.json extract:

"gulp": "^4.0.0",
    "gulp-autoprefixer": "^6.0.0",
    "gulp-chmod": "^2.0.0",
    "gulp-clean-css": "^3.10.0",
    "gulp-clone": "^2.0.1",
    "gulp-concat": "^2.6.1",
    "gulp-concat-css": "^3.1.0",
    "gulp-copy": "^4.0.0",
    "gulp-dedupe": "0.0.2",
    "gulp-flatten": "^0.4.0",
    "gulp-header": "^2.0.5",
    "gulp-if": "^2.0.2",
    "gulp-json-editor": "^2.4.3",
    "gulp-less": "^4.0.1",
    "gulp-notify": "^3.0.0",
    "gulp-plumber": "^1.1.0",
    "gulp-print": "^5.0.0",
    "gulp-rename": "^1.4.0",
    "gulp-replace": "^1.0.0",
    "gulp-rtlcss": "^1.3.0",
    "gulp-uglify": "^3.0.1",

[lubber-de]

What version is shown for the less package?
npm show less version

[j055]

3.11.1

[lubber-de]

Did you uninstall the semantic-ui 2.4.2 package before installing fomantic-ui?

[j055]

Possibly not the first time :).

[j055]

Looks like less package was an older version even though npm showed the latest. I have uninstalled and installed again, and run the build and all looks good.

Thanks for all your help.