Previous discussion about the release script: Build bzip and package from git
Install Nextcloud from source: I assume your question is how to install it with the zip files from GitHub? I don’t think we support it. As mentioned by @SysKeeper you need:
- Zip for GitHub - nextcloud/server: ☁️ Nextcloud server, a safe home for all your data
- Matching 3rdparty zip Tags · nextcloud/3rdparty · GitHub
- Matching viewer zip Tags · nextcloud/viewer · GitHub
That’s quite similar to our usual development setup. Very well possible that another app is also mandatory. Haven’t checked this way in for a while.