Linux Limitations Custom functions/aggregations are currently not supported and crash, caused by a bug in Swift. See #1071. Debugging Create and launch docker container $ docker container create swift:focal $ docker run --cap-add=SYS_PTRACE \ --security-opt seccomp=unconfined \ --security-opt apparmor=unconfined \ -i -t swift:focal bash Compile and run tests in debugger $ apt-get update && apt-get install libsqlite3-dev $ git clone https://github.com/stephencelis/SQLite.swift.git $ swift test $ lldb .build/x86_64-unknown-linux-gnu/debug/SQLite.swiftPackageTests.xctest (lldb) target create ".build/x86_64-unknown-linux-gnu/debug/SQLite.swiftPackageTests.xctest" (lldb) run