[BUG] process.env.npm_config_user_agent missing in v7

[rafgraph]

Current Behavior:

npm i --save-dev husky doesn't run the install and postinstall scripts after installing the package so the git hooks are never setup. No error is thrown. I haven't checked to see if this is unique to the husky package or not.

Expected Behavior:

For the install and postinstall scripts to run after the package is installed and the git hooks to be set up.

Steps To Reproduce:

npm i --save-dev husky
Then check to see if the git hooks have been added to .git/hooks/pre-commit (compare this to installing using npm v6)

Environment:

• OS: MacOS 10.15.6
• Node: 12.18.3
• npm: v7.0.0-beta.11

[nlf]

So there's a few things happening here:

1. We no longer display the output of install scripts unless an error occurs, this is deliberate and intended to reduce the amount of text we print during an install process.

2. The script actually is running, and failing, the problem is that it is not setting the process.exitCode to a non-0 value when an error occurs, so npm does not print the error. The error in question is

husky > Setting up git hooks
Cannot destructure property 'name' of 'which_pm_runs_1.default(...)' as it is undefined.
husky > Failed to install

3. The current version of husky (4.x) relies on the package which-pm-runs which relies on process.env.npm_config_user_agent being populated, which was removed from the environment variables that npm 7 provides. This is something that we will consider re-adding to help reduce friction.

[rafgraph]

Thanks for the detailed explanation. I don't work on husky so can't say what their thoughts are on this.