Development Build Cannot Create Database File in Container

[i2h3]

Apparently there is still something not right with the signing and entitlements for a development build. I observed that file provider extension processes of such cannot create a Realm database file in the sandbox container in which they actually should be abled to.

@nilsding found this:

% fileproviderctl check                                                            
2025-08-07 12:06:24.714 fileproviderctl[78732:13742123] 🧹 About to launch FPCK checks for 2 domains
2025-08-07 12:06:24.719 fileproviderctl[78732:13742122] 💣 FPCK failed completing: Error Domain=NSPOSIXErrorDomain Code=2 "couldn't issue sandbox extension com.apple.app-sandbox.read-write for '/Users/<redacted>/Library/CloudStorage/NextcloudDev-testuser@nextcloud.home': No such file or directory" UserInfo={NSDescription=couldn't issue sandbox extension com.apple.app-sandbox.read-write for '/Users/<redacted>/Library/CloudStorage/NextcloudDev-testuser@nextcloud.home': No such file or directory}
2025-08-07 12:06:25.987 fileproviderctl[78732:13742123] 💣 FPCK failed completing: Error Domain=FPCKDomain Code=65 "(null)"

Maybe there is something wrong or deviant in case of developer builds which also lacked the required entitlement for debugger access until recently.