The flock extension stuck at loading on Linux systems

[legendPerceptor]

The program cannot finish duckdb::LoadInternal(duckdb::ExtensionLoader&). There seems to be a deadlock. I don't see the same problem on macOS. But on Ubuntu 24.04 LOAD flock; never finishes. I built duckdb-python and flock from source. It is unrelated to duckdb's versions (I tried 1.4.0, 1.4.1 and yesterday 1.5.0). The versions of duckdb and flock match. I reproduce the same problem on both Ubuntu and EulerOS.

Have anyone successfully tested the extension on Linux? It is weird that it works perfectly on macOS but fails on Linux.

[anasdorbani]

@legendPerceptor, I tested the extension on both osx_arm64 and linux_amd64 using DuckDB versions 1.4.0, 1.4.1, and 1.4.2 with Python, and it seems to be working fine. Here’s the script I used:

import os
import duckdb
from dotenv import load_dotenv
load_dotenv()

if __name__ == "__main__":
    print("DuckDB:", duckdb.__version__)

    con = duckdb.connect(database=":memory:")
    con.execute("INSTALL flock FROM community;")
    con.execute("LOAD flock;")

    print(
        con.execute("""
                        SELECT *
                        FROM duckdb_extensions() 
                        WHERE extension_name = 'flock';""").fetchall()
    )

    openai_api_key = os.getenv("OPENAI_API_KEY")
    con.execute("CREATE SECRET (TYPE OPENAI, API_KEY ?);", [openai_api_key])

    model_alias = "test"
    base_model  = "gpt-4o"

    con.execute(f"""
        CREATE MODEL(
            '{model_alias}',
            '{base_model}',
            'openai',
            {{
                "tuple_format": "json",
                "batch_size": 32,
                "model_parameters": {{"temperature": 0.7}}
            }}
        );
    """)

    result_df = con.execute(f"""
        SELECT llm_complete(
            {{'model_name': '{model_alias}'}},
            {{'prompt': 'Talk like a duck and write a poem about a database'}}
            ) as completion;
    """).fetchdf()

    print(result_df)

The output I got:

DuckDB: 1.4.2
[('flock', True, True, '/Users/Me/.duckdb/extensions/v1.4.2/osx_arm64/flock.duckdb_extension', '', [], '7f1c36a', 'REPOSITORY', 'community')]
                                          completion
0  Quack, quack, quack,\nIn the pond, I chat with...

It works as expected on macOS. I haven’t tested on Ubuntu 24.04 with Python yet, but on macOS and Linux x86_64, specifically AlmaLinux, the extension loads and runs correctly with these versions.

[legendPerceptor]

It can possibly be a network issue. I needed to test it behind a corporate proxy, and I had a few issues even if I set HTTP_PROXY, and HTTPS_PROXY. So I wanted to build it from source and use the flock extension file directly instead of "INSTALL flock FROM community;". I used "LOAD /path/to/the/compiled/flock_extension". And it couldn't finish loading. I guess it might be trying to download it from community or otherwise I cannot explain it. I tried gdb attach to the process and it seems to get stuck at the function duckdb::LoadInternal(duckdb::ExtensionLoader&).

[legendPerceptor]

How does "INSTALL flock FROM community;" work? Where does it try to download from Internet? Maybe I can modify that part of code to make it work.

[anasdorbani]

@legendPerceptor Sorry for the delayed reply. I’m not sure if you’ve already resolved the issue, but we recently went through a refactor and made several changes.

The problem you encountered was most likely related to network access. During installation, flock also attempts to install the DuckDB json extension from the network. If you are working within an intranet or an environment without external network access, the process may get stuck.