GitHub is maintaining a namespace for each PR in the original repo, so this works as well:
npm install <user>/<repo>#pull/<id>/head
NOTE: It doesn’t seeem to be working with NPM v. 5. See the comment below.
Works with npm 7.0.23 and possibly earlier versions. See the comment below.
for example:
npm i --save-dev json-schema-faker/json-schema-faker#pull/129/head
or with yarn:
yarn add <user>/<repo>#<id>/head
for example:
yarn add json-schema-faker/json-schema-faker#129/head
Note that in Yarn case there is no pull/ segment in the package identifier.
This may be helpful if you need to automate the installation or repo / branch from where PR is originating is removed. See also Modifying an inactive pull request locally at GitHub.