Incompatible units: 'rem' and 'px' - Bootstrap 4 and Laravel Mix

Question

I just installed a fresh Laravel 5.4, and bootstrap 4 alpha 6. Laravel mix wont compile SASS: Here is one error:

    Module build failed: ModuleBuildError: Module build failed:  $input-height:                   (($font-size-base * $input-line-height) + ($input-padding-y * 2)) !default;                                 ^       Incompatible units: 'rem' and 'px'.       in /Volumes/HDD/nicolae/Dev/htdocs/test/node_modules/bootstrap/scss/_variables.scss (line 444, column 34)     at runLoaders (/Volumes/HDD/nicolae/Dev/htdocs/test/node_modules/webpack/lib/NormalModule.js:192:19)     at /Volumes/HDD/nicolae/Dev/htdocs/test/node_modules/loader-runner/lib/LoaderRunner.js:364:11     at /Volumes/HDD/nicolae/Dev/htdocs/test/node_modules/loader-runner/lib/LoaderRunner.js:230:18     at context.callback (/Volumes/HDD/nicolae/Dev/htdocs/test/node_modules/loader-runner/lib/LoaderRunner.js:111:13)     at Object.asyncSassJobQueue.push [as callback] (/Volumes/HDD/nicolae/Dev/htdocs/test/node_modules/sass-loader/lib/loader.js:57:13)     at Object.<anonymous> (/Volumes/HDD/nicolae/Dev/htdocs/test/node_modules/sass-loader/node_modules/async/dist/async.js:2262:31)     at apply (/Volumes/HDD/nicolae/Dev/htdocs/test/node_modules/sass-loader/node_modules/async/dist/async.js:20:25)     at Object.<anonymous> (/Volumes/HDD/nicolae/Dev/htdocs/test/node_modules/sass-loader/node_modules/async/dist/async.js:56:12)     at Object.callback (/Volumes/HDD/nicolae/Dev/htdocs/test/node_modules/sass-loader/node_modules/async/dist/async.js:944:16)     at options.error (/Volumes/HDD/nicolae/Dev/htdocs/test/node_modules/node-sass/lib/index.js:294:32)   @ multi ./resources/assets/js/app.js ./resources/assets/sass/app.scss 

Someone passed this? And how?

Answer 1

Solved

1. remove the bootstrap entry from package.json and replace it with "bootstrap": "4.0.0-alpha.6", in resources/assets/sass/app.scss,
2. comment out the import of variables. change the path of bootstrap to @import "node_modules/bootstrap/scss/bootstrap.scss";
3. in resources/assets/js/bootstrap.js, look for require('bootsrap-sass'); and change it to require('bootstrap');

Link!

Answer 2

It happened to me too, it's like you said, the override of some variables is the cause of this error.

To fix this just comment this line in resources/assets/sass/_variables:

$font-size-base: 14px;

In the variables if you need are using other variables that laravel provides.

reference: https://github.com/twbs/bootstrap/issues/18368