[BUG] GitHub references to dependencies slow/hang

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

As of approximately 10AM EST today, installing using a GitHub reference on NPM 6 became slow to the point where it often simply hangs. This was not the case previously, and works on NPM 7/8.

Unfortunately there are other performance issues with the v2 lock file format also related to using GitHub references that are currently preventing an upgrade to NPM > 6.

Expected Behavior

Installing a dependency using a GitHub reference should be possible.

Steps To Reproduce

1. In NPM 6
2. Run npm install github:Brightspace/d2l-fetch or npm install Brightspace/d2l-fetch
3. Both of those either hang or take 7+ minutes to install

Interestingly, npm i git+https://github.com/Brightspace/d2l-fetch.git#semver:^2 installs in 0.7 seconds.

Environment

• npm: 6.14.17
• Node.js: 14.19.2
• OS Name: macOS 12.3.1
• System Model Name: Apple MacBook Pro (2019)
• npm config:

; cli configs
metrics-registry = "https://registry.npmjs.org/"
scope = ""
user-agent = "npm/6.14.17 node/v14.19.2 darwin x64"

; node bin location = /Users/<username>/.nvm/versions/node/v14.19.2/bin/node
; cwd = /Users/<username>/source
; HOME = /Users/<username>
; "npm config ls -l" to show all defaults.

Start by reproducing the two npm install commands in npm 6.14.17 with Node.js 14.19.2, then compare them with the working git+https form and npm 7/8 behavior. Trace the npm CLI path handling GitHub dependency references; done means the reported references install without hanging or taking several minutes while preserving the faster form.