---
title: ""
url: "https://docs.yugabyte.com/stable/contribute/core-database/includes/opt-yb-build/"
---

# 

By default, when running build, third-party libraries are not built, and pre-built libraries are downloaded. The build scripts automatically install these in directories under `/opt/yb-build`. In order for the build script to write under those directories, it needs proper permissions. One way to do that is as follows:

```sh
sudo mkdir /opt/yb-build
sudo chown "$USER" /opt/yb-build
```

Alternatively, specify the build options `--no-download-thirdparty`. Note that those options may require additional, undocumented steps.