Short option for -d reads directory by name of given number

Checked out this project just now, and after playing around with the options I had the following experience:

$ alder --depth 2

 .
 ├── appearance
 │   └── start
 ├── colors
 │   └── start
 ├── editing
 │   └── start
 ├── lang
 │   └── start
 └── project
     └── start
10 directories, 0 files (0 B)
$  alder -d 2
node:internal/fs/utils:347
    throw err;
    ^

Error: ENOENT: no such file or directory, scandir '/Users/agodin/.vim/pack/2'
    at Object.readdirSync (node:fs:1451:3)
    at buildTree (/Users/agodin/.nvm/versions/node/v18.14.2/lib/node_modules/@aweary/alder/alder.js:125:20)
    at Object.<anonymous> (/Users/agodin/.nvm/versions/node/v18.14.2/lib/node_modules/@aweary/alder/alder.js:193:1)
    at Module._compile (node:internal/modules/cjs/loader:1254:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1308:10)
    at Module.load (node:internal/modules/cjs/loader:1117:32)
    at Module._load (node:internal/modules/cjs/loader:958:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
    at node:internal/main/run_main_module:23:47 {
  errno: -2,
  syscall: 'scandir',
  code: 'ENOENT',
  path: '/Users/agodin/.vim/pack/2'
}

Node.js v18.14.2

It looks like the usage of -d is setting 2 as the argument for which directory to use as the cwd.