npm removing similar packages

What I was trying to do?

Install bootstrap and ng-bootstrap

npm install --save @ng-bootstrap/ng-bootstrap
npm install --save bootstrap

What Happened Instead

bootstrap removed ng-bootstrap on running the install in reverse order, ng-bootstrap removed bootstrap.

Reproduction Steps

npm install --save @ng-bootstrap/ng-bootstrap
npm install  --save bootstrap

Platform Info

$ npm --versions
{
  npm: '6.11.3',
  ares: '1.15.0',
  cldr: '33.1',
  http_parser: '2.8.0',
  icu: '62.1',
  modules: '64',
  napi: '3',
  nghttp2: '1.34.0',
  node: '10.15.2',
  openssl: '1.1.0j',
  tz: '2018e',
  unicode: '11.0',
  uv: '1.23.2',
  v8: '6.8.275.32-node.12',
  zlib: '1.2.11'
}

$ node -p process.platform
darwin

I was not able to reproduce following these steps and matching setup (Darwin and npm 6.11.3). Were you seeing this as part of a big package rather than a small reproduce?

$ npm init -y
...

$ npm install --save @ng-bootstrap/ng-bootstrap
...
+ @ng-bootstrap/ng-bootstrap@5.1.1
added 2 packages from 2 contributors and audited 2 packages in 2.423s
found 0 vulnerabilities

$ npm install --save bootstrap
...
+ bootstrap@4.3.1
added 1 package from 2 contributors and audited 3 packages in 0.643s
found 0 vulnerabilities

$ ls node_modules 
@ng-bootstrap	bootstrap	tslib