Hi @Brandyn_Bennett! Good question. At the moment psql and pg_dump are available to running services and in the web shell, but not at build time. We’ll go ahead and add these to the build environment for you.
Depending on your use case, you may be able to define an initialDeployHook that does the data copying instead of making this part of your build process. The initialDeployHook is a command that runs only once, after your preview environment is deployed for the first time. It should already have access to psql and pg_dump.
See Preview Environments | Render · Cloud Hosting for Developers for more on the initialDeployHook.