It worked when installing inside the project folder and did not work when installing outside the project folder:

  // Success: Running in the project folder.
  me:~/deprank$ yarn add deprank
  yarn add v1.22.19
  warning ../package.json: No license field
  [1/5] Validating package.json...
  [2/5] Resolving packages...
  [3/5] Fetching packages...
  [4/5] Linking dependencies...
  [5/5] Building fresh packages...
  success Saved lockfile.
  success Saved 1 new dependency.
  info Direct dependencies
  └─ [email protected]
  info All dependencies
  └─ [email protected]
  $ tsdx build
  @rollup/plugin-replace: 'preventAssignment' currently defaults to false. It is recommended to set this option to `true`, as the next major version will default this option to `true`.
  @rollup/plugin-replace: 'preventAssignment' currently defaults to false. It is recommended to set this option to `true`, as the next major version will default this option to `true`.
   Creating entry file 602 ms
   Building modules 1.4 secs
  Done in 5.95s.
  me:~/deprank$ yarn run deprank src/
  yarn run v1.22.19
  warning ../package.json: No license field
  $ /home/dan/deprank/node_modules/.bin/deprank src/
  | Filename     | Lines | Dependents | PageRank |
  ------------------------------------------------
  | src/index.ts | 280   | 0          | 1.000000 |
  Done in 0.55s.
  me:~/deprank$ yarn run deprank .
  yarn run v1.22.19
  warning ../package.json: No license field
  $ /home/me/deprank/node_modules/.bin/deprank .
  | Filename                           | Lines | Dependents | PageRank 
  ----------------------------------------------------------------------
  | fixtures/core.js                   | 3     | 1          | 0.191112 |
  | fixtures/utils.js                  | 4     | 3          | 0.180576 |
  | fixtures/user/user.js              | 4     | 1          | 0.088966 |
  | src/index.ts                       | 280   | 1          | 0.069599 |
  | fixtures/todo.js                   | 6     | 1          | 0.060405 |
  | fixtures/user/index.js             | 1     | 1          | 0.060405 |
  | dist/deprank.cjs.development.js    | 829   | 1          | 0.053610 |
  | dist/deprank.cjs.production.min.js | 2     | 1          | 0.053610 |
  | fixtures/concepts.js               | 4     | 1          | 0.053610 |
  | dist/deprank.esm.js                | 820   | 0          | 0.037621 |
  | dist/index.d.ts                    | 36    | 0          | 0.037621 |
  | dist/index.js                      | 8     | 0          | 0.037621 |
  | fixtures/index.js                  | 4     | 0          | 0.037621 |
  | test/deprank.test.ts               | 28    | 0          | 0.037621 |
  Done in 0.60s.

  ------------------------------------------------------------------------------------------------------------------------------------
  // Failure: Running outside of the project folder:
  me:~$ yarn add deprank
  yarn add v1.22.19
  warning package.json: No license field
  warning package-lock.json found. Your project contains lock files generated by tools other than Yarn. It is advised not to mix package managers in order to avoid resolution inconsistencies caused by unsynchronized lock files. To clear this warning, remove package-lock.json.
  warning No license field
  [1/4] Resolving packages...
  [2/4] Fetching packages...
  [3/4] Linking dependencies...
  [4/4] Building fresh packages...
  success Saved lockfile.
  warning No license field
  success Saved 3 new dependencies.
  info Direct dependencies
  ├─ [email protected]
  └─ [email protected]
  info All dependencies
  ├─ [email protected]
  ├─ [email protected]
  └─ [email protected]
  Done in 4.95s.

  me:~$ yarn run deprank deprank/
  yarn run v1.22.19
  warning package.json: No license field
  $ /home/me/node_modules/.bin/deprank deprank/
  | Filename                                   | Lines | Dependents | PageRank |
  ------------------------------------------------------------------------------
  | deprank/fixtures/core.js                   | 3     | 1          | 0.223479 |
  | deprank/fixtures/utils.js                  | 4     | 3          | 0.211161 |
  | deprank/fixtures/user/user.js              | 4     | 1          | 0.104035 |
  | deprank/fixtures/todo.js                   | 6     | 1          | 0.070637 |
  | deprank/fixtures/user/index.js             | 1     | 1          | 0.070637 |
  | deprank/dist/deprank.cjs.development.js    | 829   | 1          | 0.062691 |
  | deprank/dist/deprank.cjs.production.min.js | 2     | 1          | 0.062691 |
  | deprank/fixtures/concepts.js               | 4     | 1          | 0.062691 |
  | deprank/dist/deprank.esm.js                | 820   | 0          | 0.043993 |
  | deprank/dist/index.js                      | 8     | 0          | 0.043993 |
  | deprank/fixtures/index.js                  | 4     | 0          | 0.043993 |
  Done in 0.28s.