[webpack-cli 4.0.0] Unknown argument: --env.source=src/examples/*

[doberkofler]

Bug report

After migrating to webpack cli 4.0.0 i get the following error:

~/MyDev/ljs_app/trunk/periscope $ npx webpack --progress --env.source="src/examples/*"
[webpack-cli] Unknown argument: --env.source=src/examples/*
? Which flags do you want to use? …
✔ --entry: The entry point(s) of your application e.g. ./src/main.js
✔ --config: Provide path to a webpack configuration file e.g. ./webpack.config.js
✖ Which flags do you want to use? · No items were selected
[webpack-cli] Action Interrupted, use webpack-cli help to see possible options.

What is the current behavior?

If the current behavior is a bug, please provide the steps to reproduce.

npx webpack --progress --env.source="src/examples/*"

What is the expected behavior?

Other relevant information:
webpack version: 5.0.0
Node.js version: 14.13.0
Operating System: macOS 10.15.7
Additional tools:

[anshumanv]

This format is no longer supported in v4, we're working to enhance it here - #1939

Duplicate of #1932

[nevcos]

@anshumanv This breaking change is not referred on https://webpack.js.org/migrate/5/ or CHANGELOG, it's worth adding it.

This change is highly inconvenient because it affects CI scripts, which in our case need to work both with webpack 4 and 5:

# webpack-cli 3:
webpack --env.myFlag=true 
# runs ok, value available on script as `options.myFlag`

# webpack-cli 4:
webpack --env.myFlag=true
[webpack-cli] Error: Unknown option '--env.myFlag=true'

Is there any syntax that works on both webpack-cli v3 and v4?

Thanks!

[alexander-akait]

@nevcos --env platform=staging --env production --env foo.bar=baz

[nevcos]

@alexander-akait It doesn't work the same way:

# webpack-cli 3:
webpack --env.myFlag=true # options is an object: {"myFlag":"true"}
webpack --env myFlag=true # options is a string: "myFlag=true"

# webpack-cli 4:
webpack --env myFlag=true # options is an object: {"WEBPACK_BUNDLE":true,"WEBPACK_BUILD":true,"myFlag":"true"}

[alexander-akait]

If you need boolean value, you need just use --env myFlag (without any values)

[nevcos]

@alexander-akait It was just an example, in my case I need to send a string URL for source maps location.
I'll fix the CI script with an ugly if [[ ${WEBPACK_VERSION} == 4* ]], hopefully I'll be able to remove it soon 😅.