Is there an existing issue for this?

• I have searched the existing issues

This issue exists in the latest npm version

• I am using the latest npm

Current Behavior

Trying to set the prefix config option using environment variables as documented here:

https://docs.npmjs.com/cli/v8/using-npm/config#environment-variables

The current behaviour is that the output from these two commands is different.

NPM_CONFIG_PREFIX=dingle npm config ls -l | grep prefix

npm --prefix dingle config ls -l | grep prefix

In addition, currently this command:

NPM_CONFIG_PREFIX=dingle npm install doodle.css

does not install into the folder dingle whereas this command does:

npm install --prefix dingle doodle.css

Expected Behavior

Expected behaviour setting the prefix via either NPM_CONFIG_PREFIX or --prefix has the same results and installs into the specified folder.

Steps To Reproduce

1. $ npm --version -> 8.1.2
2. Run NPM_CONFIG_PREFIX=dingle npm config ls -l | grep prefix and npm --prefix dingle config ls -l | grep prefix
3. Observe the output is different

Environment

• npm: 8.1.2
• Node.js: v16.13.1
• OS Name: Ubuntu Linux
• System Model Name: Dell XPS 13
• npm config:

; "user" config from /home/chrism/.npmrc

//registry.npmjs.org/:_authToken = (protected) 
unsafe-perm = true 

; node bin location = /home/chrism/.nvm/versions/node/v16.13.1/bin/node
; cwd = /home/chrism/dev/npm-prefix-test
; HOME = /home/chrism
; Run `npm config ls -l` to show all defaults.