test failed in CI:`test_instance_migration_compatible_cpu_platforms`

This test failed on a CI run on #9578:

https://github.com/oxidecomputer/omicron/pull/9679/checks?check_run_id=60860072238

Log showing the specific test failure:

https://buildomat.eng.oxide.computer/wg/0/details/01KFD3PATFZJ4F68EQGBRZ9RKK/yiP1BfMdP14Iwhgtspjx6oazyfoJEko6xrIg156g8onreeHY/01KFD3PRT38K6QRBJYEKVM9ZP0#S8222

Excerpt from the log showing the failure:

        FAIL [  39.960s] (1485/2651) omicron-nexus::test_all integration_tests::instances::test_instance_migration_compatible_cpu_platforms
  stdout ───

    running 1 test
    test integration_tests::instances::test_instance_migration_compatible_cpu_platforms ... FAILED

    failures:

    failures:
        integration_tests::instances::test_instance_migration_compatible_cpu_platforms

    test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 598 filtered out; finished in 39.33s
    
  stderr ───
    log file: /var/tmp/omicron_tmp/test_all-980979e68d70c319-test_instance_migration_compatible_cpu_platforms.29584.0.log
    note: configured to log to "/var/tmp/omicron_tmp/test_all-980979e68d70c319-test_instance_migration_compatible_cpu_platforms.29584.0.log"
    DB URL: postgresql://root@[::1]:37273/omicron?sslmode=disable
    DB address: [::1]:37273
    log file: /var/tmp/omicron_tmp/test_all-980979e68d70c319-test_instance_migration_compatible_cpu_platforms.29584.2.log
    note: configured to log to "/var/tmp/omicron_tmp/test_all-980979e68d70c319-test_instance_migration_compatible_cpu_platforms.29584.2.log"

    thread 'integration_tests::instances::test_instance_migration_compatible_cpu_platforms' (2) panicked at sled-agent/src/sim/collection.rs:274:65:
    called `Result::unwrap()` on an `Err` value: InternalError { internal_message: "Communication Error: error sending request for url (http://127.0.0.1:42892/vmms/c364e49d-1fdf-4d47-a843-f64f4d710717)" }
    stack backtrace:
       0: __rustc::rust_begin_unwind
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/std/src/panicking.rs:698:5
       1: core::panicking::panic_fmt
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/panicking.rs:75:14
       2: core::result::unwrap_failed
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/result.rs:1855:5
       3: unwrap<(), omicron_common::api::external::error::Error>
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/result.rs:1226:23
       4: {async_fn#0}<omicron_sled_agent::sim::instance::SimInstance>
                 at /work/oxidecomputer/omicron/sled-agent/src/sim/collection.rs:274:65
       5: {async_fn#0}
                 at /work/oxidecomputer/omicron/sled-agent/src/sim/sled_agent.rs:564:58
       6: {async_fn#0}
                 at /work/oxidecomputer/omicron/sled-agent/src/sim/http_entrypoints.rs:1039:38
       7: {async_block#0}<alloc::sync::Arc<omicron_sled_agent::sim::sled_agent::SledAgent, alloc::alloc::Global>, fn(dropshot::handler::RequestContext<alloc::sync::Arc<omicron_sled_agent::sim::sled_agent::SledAgent, alloc::alloc::Global>>, dropshot::extractor::path::Path<sled_agent_types_versions::v1::instance::VmmPathParam>) -> omicron_sled_agent::sim::http_entrypoints::{impl#1}::from::instance_poke_post::{async_fn_env#0}, omicron_sled_agent::sim::http_entrypoints::{impl#1}::from::instance_poke_post::{async_fn_env#0}, dropshot::handler::HttpResponseUpdatedNoContent, dropshot::error::HttpError, dropshot::extractor::path::Path<sled_agent_types_versions::v1::instance::VmmPathParam>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/dropshot-0.16.6/src/handler.rs:664:78
       8: poll<alloc::boxed::Box<(dyn core::future::future::Future<Output=core::result::Result<http::response::Response<dropshot::body::Body>, dropshot::handler::HandlerError>> + core::marker::Send), alloc::alloc::Global>>
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/future/future.rs:133:9
       9: {async_block#0}<alloc::sync::Arc<omicron_sled_agent::sim::sled_agent::SledAgent, alloc::alloc::Global>, fn(dropshot::handler::RequestContext<alloc::sync::Arc<omicron_sled_agent::sim::sled_agent::SledAgent, alloc::alloc::Global>>, dropshot::extractor::path::Path<sled_agent_types_versions::v1::instance::VmmPathParam>) -> omicron_sled_agent::sim::http_entrypoints::{impl#1}::from::instance_poke_post::{async_fn_env#0}, (dropshot::extractor::path::Path<sled_agent_types_versions::v1::instance::VmmPathParam>), dropshot::handler::HttpResponseUpdatedNoContent>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/dropshot-0.16.6/src/handler.rs:793:16
      10: poll<alloc::boxed::Box<(dyn core::future::future::Future<Output=core::result::Result<http::response::Response<dropshot::body::Body>, dropshot::handler::HandlerError>> + core::marker::Send), alloc::alloc::Global>>
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/future/future.rs:133:9
      11: {async_block#0}<alloc::sync::Arc<omicron_sled_agent::sim::sled_agent::SledAgent, alloc::alloc::Global>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/dropshot-0.16.6/src/server.rs:937:69
      12: tokio::runtime::task::core::Core<T,S>::poll::{{closure}}
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/task/core.rs:365:24
      13: with_mut<tokio::runtime::task::core::Stage<dropshot::server::http_request_handle::{async_fn#0}::{async_block_env#0}<alloc::sync::Arc<omicron_sled_agent::sim::sled_agent::SledAgent, alloc::alloc::Global>>>, core::task::poll::Poll<()>, tokio::runtime::task::core::{impl#6}::poll::{closure_env#0}<dropshot::server::http_request_handle::{async_fn#0}::{async_block_env#0}<alloc::sync::Arc<omicron_sled_agent::sim::sled_agent::SledAgent, alloc::alloc::Global>>, alloc::sync::Arc<tokio::runtime::scheduler::current_thread::Handle, alloc::alloc::Global>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/loom/std/unsafe_cell.rs:16:9
      14: poll<dropshot::server::http_request_handle::{async_fn#0}::{async_block_env#0}<alloc::sync::Arc<omicron_sled_agent::sim::sled_agent::SledAgent, alloc::alloc::Global>>, alloc::sync::Arc<tokio::runtime::scheduler::current_thread::Handle, alloc::alloc::Global>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/task/core.rs:354:30
      15: tokio::runtime::task::harness::poll_future::{{closure}}
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/task/harness.rs:535:30
      16: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/panic/unwind_safe.rs:274:9
      17: do_call<core::panic::unwind_safe::AssertUnwindSafe<tokio::runtime::task::harness::poll_future::{closure_env#0}<dropshot::server::http_request_handle::{async_fn#0}::{async_block_env#0}<alloc::sync::Arc<omicron_sled_agent::sim::sled_agent::SledAgent, alloc::alloc::Global>>, alloc::sync::Arc<tokio::runtime::scheduler::current_thread::Handle, alloc::alloc::Global>>>, core::task::poll::Poll<()>>
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/std/src/panicking.rs:590:40
      18: __rust_try
      19: catch_unwind<core::task::poll::Poll<()>, core::panic::unwind_safe::AssertUnwindSafe<tokio::runtime::task::harness::poll_future::{closure_env#0}<dropshot::server::http_request_handle::{async_fn#0}::{async_block_env#0}<alloc::sync::Arc<omicron_sled_agent::sim::sled_agent::SledAgent, alloc::alloc::Global>>, alloc::sync::Arc<tokio::runtime::scheduler::current_thread::Handle, alloc::alloc::Global>>>>
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/std/src/panicking.rs:553:19
      20: catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<tokio::runtime::task::harness::poll_future::{closure_env#0}<dropshot::server::http_request_handle::{async_fn#0}::{async_block_env#0}<alloc::sync::Arc<omicron_sled_agent::sim::sled_agent::SledAgent, alloc::alloc::Global>>, alloc::sync::Arc<tokio::runtime::scheduler::current_thread::Handle, alloc::alloc::Global>>>, core::task::poll::Poll<()>>
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/std/src/panic.rs:359:14
      21: tokio::runtime::task::harness::poll_future
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/task/harness.rs:523:18
      22: tokio::runtime::task::harness::Harness<T,S>::poll_inner
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/task/harness.rs:210:27
      23: tokio::runtime::task::harness::Harness<T,S>::poll
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/task/harness.rs:155:20
      24: tokio::runtime::task::raw::poll
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/task/raw.rs:325:13
      25: tokio::runtime::task::raw::RawTask::poll
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/task/raw.rs:255:18
      26: tokio::runtime::task::LocalNotified<S>::run
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/task/mod.rs:509:13
      27: tokio::runtime::scheduler::current_thread::CoreGuard::block_on::{{closure}}::{{closure}}
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:789:30
      28: with_budget<(), tokio::runtime::scheduler::current_thread::{impl#8}::block_on::{closure#0}::{closure_env#1}<core::pin::Pin<&mut core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/task/coop/mod.rs:167:5
      29: budget<(), tokio::runtime::scheduler::current_thread::{impl#8}::block_on::{closure#0}::{closure_env#1}<core::pin::Pin<&mut core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/task/coop/mod.rs:133:5
      30: {closure#0}<(), tokio::runtime::scheduler::current_thread::{impl#8}::block_on::{closure#0}::{closure_env#1}<core::pin::Pin<&mut core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:368:43
      31: tokio::runtime::scheduler::current_thread::Context::enter
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:432:19
      32: tokio::runtime::scheduler::current_thread::Context::run_task
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:368:28
      33: {closure#0}<core::pin::Pin<&mut core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:785:43
      34: tokio::runtime::scheduler::current_thread::CoreGuard::enter::{{closure}}
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:829:68
      35: tokio::runtime::context::scoped::Scoped<T>::set
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/context/scoped.rs:40:9
      36: tokio::runtime::context::set_scheduler::{{closure}}
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/context.rs:176:38
      37: try_with<tokio::runtime::context::Context, tokio::runtime::context::set_scheduler::{closure_env#0}<(alloc::boxed::Box<tokio::runtime::scheduler::current_thread::Core, alloc::alloc::Global>, core::option::Option<()>), tokio::runtime::scheduler::current_thread::{impl#8}::enter::{closure_env#0}<tokio::runtime::scheduler::current_thread::{impl#8}::block_on::{closure_env#0}<core::pin::Pin<&mut core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>>, core::option::Option<()>>>, (alloc::boxed::Box<tokio::runtime::scheduler::current_thread::Core, alloc::alloc::Global>, core::option::Option<()>)>
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/std/src/thread/local.rs:315:12
      38: std::thread::local::LocalKey<T>::with
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/std/src/thread/local.rs:279:20
      39: tokio::runtime::context::set_scheduler
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/context.rs:176:17
      40: tokio::runtime::scheduler::current_thread::CoreGuard::enter
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:829:27
      41: tokio::runtime::scheduler::current_thread::CoreGuard::block_on
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:729:24
      42: {closure#0}<core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:200:33
      43: tokio::runtime::context::runtime::enter_runtime
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/context/runtime.rs:65:16
      44: block_on<core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:188:9
      45: tokio::runtime::runtime::Runtime::block_on_inner
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/runtime.rs:368:52
      46: block_on<core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/runtime.rs:342:18
      47: test_instance_migration_compatible_cpu_platforms
                 at ./tests/integration_tests/instances.rs:1111:1
      48: test_all::integration_tests::instances::test_instance_migration_compatible_cpu_platforms::{{closure}}
                 at ./tests/integration_tests/instances.rs:1114:2
      49: core::ops::function::FnOnce::call_once
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/ops/function.rs:250:5
      50: core::ops::function::FnOnce::call_once
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/ops/function.rs:250:5
    note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

    thread 'integration_tests::instances::test_instance_migration_compatible_cpu_platforms' (2) panicked at clients/sled-agent-client/src/lib.rs:385:14:
    instance_finish_transition() failed unexpectedly: reqwest::Error { kind: Request, url: "http://[::1]:63165/vmms/c364e49d-1fdf-4d47-a843-f64f4d710717/poke", source: hyper_util::client::legacy::Error(SendRequest, hyper::Error(IncompleteMessage)) }
    stack backtrace:
       0: __rustc::rust_begin_unwind
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/std/src/panicking.rs:698:5
       1: core::panicking::panic_fmt
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/panicking.rs:75:14
       2: core::result::unwrap_failed
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/result.rs:1855:5
       3: core::result::Result<T,E>::expect
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/result.rs:1178:23
       4: {async_block#0}
                 at /work/oxidecomputer/omicron/clients/sled-agent-client/src/lib.rs:385:14
       5: poll<alloc::boxed::Box<(dyn core::future::future::Future<Output=()> + core::marker::Send), alloc::alloc::Global>>
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/future/future.rs:133:9
       6: {async_fn#0}
                 at ./tests/integration_tests/instances.rs:8827:72
       7: {async_fn#0}
                 at ./tests/integration_tests/instances.rs:1191:44
       8: {async_block#0}
                 at ./tests/integration_tests/instances.rs:1111:1
       9: poll<&mut dyn core::future::future::Future<Output=()>>
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/future/future.rs:133:9
      10: poll<&mut core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/future/future.rs:133:9
      11: {closure#0}<core::pin::Pin<&mut core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:742:70
      12: with_budget<core::task::poll::Poll<()>, tokio::runtime::scheduler::current_thread::{impl#8}::block_on::{closure#0}::{closure#0}::{closure_env#0}<core::pin::Pin<&mut core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/task/coop/mod.rs:167:5
      13: budget<core::task::poll::Poll<()>, tokio::runtime::scheduler::current_thread::{impl#8}::block_on::{closure#0}::{closure#0}::{closure_env#0}<core::pin::Pin<&mut core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/task/coop/mod.rs:133:5
      14: {closure#0}<core::pin::Pin<&mut core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:742:25
      15: tokio::runtime::scheduler::current_thread::Context::enter
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:432:19
      16: {closure#0}<core::pin::Pin<&mut core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:741:44
      17: tokio::runtime::scheduler::current_thread::CoreGuard::enter::{{closure}}
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:829:68
      18: tokio::runtime::context::scoped::Scoped<T>::set
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/context/scoped.rs:40:9
      19: tokio::runtime::context::set_scheduler::{{closure}}
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/context.rs:176:38
      20: try_with<tokio::runtime::context::Context, tokio::runtime::context::set_scheduler::{closure_env#0}<(alloc::boxed::Box<tokio::runtime::scheduler::current_thread::Core, alloc::alloc::Global>, core::option::Option<()>), tokio::runtime::scheduler::current_thread::{impl#8}::enter::{closure_env#0}<tokio::runtime::scheduler::current_thread::{impl#8}::block_on::{closure_env#0}<core::pin::Pin<&mut core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>>, core::option::Option<()>>>, (alloc::boxed::Box<tokio::runtime::scheduler::current_thread::Core, alloc::alloc::Global>, core::option::Option<()>)>
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/std/src/thread/local.rs:315:12
      21: std::thread::local::LocalKey<T>::with
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/std/src/thread/local.rs:279:20
      22: tokio::runtime::context::set_scheduler
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/context.rs:176:17
      23: tokio::runtime::scheduler::current_thread::CoreGuard::enter
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:829:27
      24: tokio::runtime::scheduler::current_thread::CoreGuard::block_on
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:729:24
      25: {closure#0}<core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:200:33
      26: tokio::runtime::context::runtime::enter_runtime
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/context/runtime.rs:65:16
      27: block_on<core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/scheduler/current_thread/mod.rs:188:9
      28: tokio::runtime::runtime::Runtime::block_on_inner
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/runtime.rs:368:52
      29: block_on<core::pin::Pin<&mut dyn core::future::future::Future<Output=()>>>
                 at /home/build/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/runtime/runtime.rs:342:18
      30: test_instance_migration_compatible_cpu_platforms
                 at ./tests/integration_tests/instances.rs:1111:1
      31: test_all::integration_tests::instances::test_instance_migration_compatible_cpu_platforms::{{closure}}
                 at ./tests/integration_tests/instances.rs:1114:2
      32: core::ops::function::FnOnce::call_once
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/ops/function.rs:250:5
      33: core::ops::function::FnOnce::call_once
                 at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/ops/function.rs:250:5
    note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
    WARN: dropped CockroachInstance without cleaning it up first (there may still be a child process running and a temporary directory leaked)
    WARN: temporary directory leaked: "/var/tmp/omicron_tmp/.tmpCMPRSZ"
    	If you would like to access the database for debugging, run the following:

    	# Run the database
    	cargo xtask db-dev run --no-populate --store-dir "/var/tmp/omicron_tmp/.tmpCMPRSZ/data"
    	# Access the database. Note the port may change if you run multiple databases.
    	cockroach sql --host=localhost:32221 --insecure
    WARN: dropped ClickHouse process without cleaning it up first (there may still be a child process running (PID 29592) and a temporary directory leaked, /var/tmp/omicron_tmp/test_all-980979e68d70c319-test_instance_migration_compatible_cpu_platforms.29584.1-clickhouse-CckUf3)
    failed to clean up ClickHouse data dir:
    - /var/tmp/omicron_tmp/test_all-980979e68d70c319-test_instance_migration_compatible_cpu_platforms.29584.1-clickhouse-CckUf3: File exists (os error 17)
    WARN: dropped DendriteInstance without cleaning it up first (there may still be a child process running and a temporary directory leaked)
    WARN: dendrite temporary directory leaked: /var/tmp/omicron_tmp/.tmpEiRcIY
    WARN: dropped MgdInstance without cleaning it up first (there may still be a child process running and a temporary directory leaked)
    WARN: mgd temporary directory leaked: /var/tmp/omicron_tmp/.tmpnYOANp

Start with integration_tests::instances::test_instance_migration_compatible_cpu_platforms and the linked CI failure log. Inspect sled-agent/src/sim/collection.rs at line 274, where the panic occurs, and trace the failed request to /vmms. Done means the test completes successfully in CI without this communication error.