CI flake: C# smoketests fail during pre_publish with Broken pipe

[clockwork-labs-bot]

Created by CI Gremlin from a manually supplied failed GitHub Actions job.

Tests:

• smoketests::column_defaults::test_csharp_column_defaults
• smoketests::http_routes::csharp_handle_request_body
• smoketests::http_routes::csharp_http_handler_observes_full_external_uri
• smoketests::http_routes::csharp_http_handlers_tutorial_say_hello_route_works
• smoketests::http_routes::csharp_http_routes_are_strict_for_root_paths

Error:
thread 'smoketests::column_defaults::test_csharp_column_defaults' (45251) panicked at crates/smoketests/tests/smoketests/column_defaults.rs:44:10:
called Result::unwrap() on an Err value: spacetime ["publish", "--server", "http://127.0.0.1:37351", "--module-path", "/tmp/.tmp7WP2kN/column-defaults-csharp-initial/spacetimedb", "--dotnet-version", "10", "--...

Failed job runs:

• https://github.com/clockworklabs/SpacetimeDB/actions/runs/31190020204/job/92908855826 (Smoketests (Linux), attempt 1 -> manual)

Timeout detection:

• none

Context:

• Requested from #ci-gremlin by Zeke.
• Original public PR: Middleware and metric to track per-database HTTP response egress #5611 (Middleware and metric to track per-database HTTP response egress #5611)

[clockwork-labs-bot]

Followup investigation for the exact linked job.

Exact failure inspected:

• Workflow run: 31190020204, attempt 1
• Job: 92908855826, Smoketests (Linux)
• PR: Middleware and metric to track per-database HTTP response egress #5611, head 4ac33fd3cfe681943d91c668985af963bcfecfa1
• Runner: ghr-github-self-hosted-ubuntu-14900k-07-spacetimedb-14-e49f463b

Failure signature:

• cargo ci smoketests ran 238 tests: 228 passed, 10 failed.
• All failures were C# smoketests. The representative failure was smoketests::column_defaults::test_csharp_column_defaults.
• The C# module build completed successfully, then spacetime publish failed while uploading to the local test server endpoint /v1/database/.../pre_publish.
• The client-side error was error writing a body to connection / Broken pipe (os error 32).
• The same publish/pre_publish broken-pipe pattern appeared in the failed C# HTTP route, template, and view smoketests, including both .NET 10 and .NET 8 template publishes.
• Nearby C++ HTTP route smoketests passed before the C# group started failing, so this looks like a C# publish/pre_publish transport failure rather than a general runner or local-server startup failure.

Failed tests:

• smoketests::column_defaults::test_csharp_column_defaults
• smoketests::http_routes::csharp_handle_request_body
• smoketests::http_routes::csharp_http_handler_observes_full_external_uri
• smoketests::http_routes::csharp_http_handlers_tutorial_say_hello_route_works
• smoketests::http_routes::csharp_http_routes_are_strict_for_root_paths
• smoketests::http_routes::csharp_http_routes_end_to_end
• smoketests::templates::test_template_basic_cs
• smoketests::templates::test_template_chat_console_cs
• smoketests::views::test_csharp_count_view_subscription_refreshes
• smoketests::views::test_csharp_query_builder_view_query

Suggested title: CI flake: C# smoketests fail during pre_publish with Broken pipe

Duplicate search:

• Searched for the exact failing test names, dotnet-version 10, spacetime publish failed for C# server, pre_publish, and Broken pipe (os error 32).
• I did not find an existing public flake tracker with this same signature.

Leaving this open as a new C# smoketest/pre_publish flake tracker.

[gefjon]

Not a flake, a real bug introduced by #5611 . Fixed within that PR before merging.