This message was deleted.

Using Java 21 is already your first problem. There is not yet any Gradle version that officially supports running with Java 21: https://docs.gradle.org/current/userguide/compatibility.html Besides that, it fails to create

/opt/flutter/packages/flutter_tools/gradle/.gradle

, so I guess the user you run the build with does not have write permissions in this folder. I have no idea about Flutter, so I don't know whether that is the default and intended

GRADLE_USER_HOME

or whether you "accidentally" set it to that directory instead of using the default of

~/.gradle

. You might want to paste a link to this question in #C03EM93810S or ask in some Flutter community eventually.