Question: I received an error when I build the app on Xcode:

```
/bin/sh: yarn: command not found
make: *** [LocalMediaPicker/Sources/LocalMediaPicker/Generated/i18n.stamp] Error 127
Command PhaseScriptExecution failed with a nonzero exit code

```

But I run `which yarn` in terminal get `/opt/homebrew/bin/yarn`, not sure why the Xcode cannot find `yarn`

Xcode version: Version 13.4.1 (13F100)

yarn version: 1.22.17

OS: Monterey Version 12.3

Update: Tried `npm i -g yarn`

```
> yarn@1.22.19 preinstall /opt/homebrew/lib/node_modules/yarn
> :; (node ./preinstall.js > /dev/null 2>&1 || true)

npm ERR! code EEXIST
npm ERR! syscall symlink
npm ERR! path ../lib/node_modules/yarn/bin/yarn.js
npm ERR! dest /opt/homebrew/bin/yarn
npm ERR! errno -17
npm ERR! EEXIST: file already exists, symlink '../lib/node_modules/yarn/bin/yarn.js' -> '/opt/homebrew/bin/yarn'
npm ERR! File exists: /opt/homebrew/bin/yarn
npm ERR! Remove the existing file and try again, or run npm
npm ERR! with --force to overwrite files recklessly.

```

Answer: 
`yarn` is installed in a location that isn't in the `PATH` used by the build phase scripts. There's two ways I can think of to change the script so it should work.

---

Before calling `yarn`, add the path containing the executable to the `PATH` the script will use.

```
export PATH="$PATH:/opt/homebrew/bin"

yarn ...

```

---

Call `yarn` using the full path to the executable instead of just the name.

```
/opt/homebrew/bin/yarn ...

```
```
sudo npm install -g npm

```

then

```
sudo nom install -g yarn

```

**Reboot your system** this worked for me. There probably is a problem with mapping so that could be your problem.