Some issues with npm@7

Setup

git clone https://github.com/targos/npm7-cra.git
cd npm7-cra

Steps to reproduce

Issue 1: npm ci changes package.json

npm ci
git status

Now the package.json file has uncommitted changes (reordered elements in dependencies).

Note that this is new and did not happen with 7.0.0-beta.10.

Issue 2: npm ci prints an error without context

npm ci

Prints: npm WARN Error: Unsupported engine (first line of the output).

Issue 3: npm i always pretends it "added 4 packages"

npm ci
npm i
npm i
npm i

Everytime npm i is executed, the output is:

added 4 packages, and audited 1729 packages in 2s

69 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities

Issue 4: npm i react@17 never ends

npm ci
npm i react@17

With npm@7, the command never ends and cannot even be killed with CTRL+C. With npm@6, it ends with an error (because there is no matching version).