Can't run encore dev - symfony

Question

Why i have this erros when I want to use yarn run encore dev ? When I want to add sass i get warning " > sass-loader#6.0.7" has unmet peer dependency "webpack#^2.0.0 || ^3.0.0 || ^4.0.0". But why ? Symfony 4. I cant install from github this modules npm install --save child_process fork-ts-checker-webpack-plugin fs module net readline spdx-exceptions spdx-license-ids spdx-license-ids/deprecated
yarn run encore dev
yarn run v1.5.1
$ c:\xampp\htdocs\dashboard\Symfony\pppp\node_modules.bin\encore dev
Running webpack ...
ERROR Failed to compile with 50 errors 09:48:38
These dependencies were not found:
child_process in ./node_modules/execa/index.js, ./node_modules/execa/node_modules/cross-spawn/index.js and 1 other
fork-ts-checker-webpack-plugin in ./node_modules/#symfony/webpack-encore/lib/plugins/forked-ts-types.js
fs in ./node_modules/#symfony/webpack-encore/lib/WebpackConfig.js, ./node_modules/#symfony/webpack-encore/lib/config/parse-runtime.js and 35 others
module in (webpack)/lib/NormalModule.js, (webpack)/lib/node/NodeTargetPlugin.js
net in ./node_modules/growly/lib/gntp.js, ./node_modules/node-notifier/lib/checkGrowl.js
readline in ./node_modules/friendly-errors-webpack-plugin/src/output.js
spdx-exceptions in ./node_modules/spdx-expression-parse/scan.js
spdx-license-ids in ./node_modules/spdx-correct/index.js, ./node_modules/spdx-expression-parse/scan.js
spdx-license-ids/deprecated in ./node_modules/spdx-expression-parse/scan.js
To install them, you can run: npm install --save child_process fork-ts-checker-webpack-plugin fs module net readline spdx-exceptions spdx-license-ids spdx-license-ids/deprecated
error An unexpected error occurred: "Command failed.
Exit code: 2
Command: C:\WINDOWS\system32\cmd.exe
Arguments: /d /s /c c:\xampp\htdocs\dashboard\Symfony\pppp\
ode_modules\.bin\encore dev
Directory: c:\xampp\htdocs\dashboard\Symfony\pppp
Output:
".
info If you think this is a bug, please open a bug report with the information provided in "c:\xampp\htdocs\dashboard\Symfony\swisscar\yarn-error.log".
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

Answer 1

I suspect you have solved this issue by now but if not the solution to the problem lie in reading the error message. For starters the 'yarn run encore dev' is complaining that some dependencies required by some of the libraries your application depend on, are missing from your installation of node.