Inferring async overload in top-level code

Using Swift
1

I'm attempting to write a simple script - i.e. one file, largely top-level code - that uses PostgresNIO's async interface. I'm running into trouble with what appears to be Swift inferring the wrong (non-async) overloads in calls to various PostgresNIO functions:

import Foundation
import Logging
import PostgresNIO

let logger = Logger(label: "example")

let dbConfig = PostgresConnection.Configuration(
    unixSocketPath: "/run/postgresql/.s.PGSQL.5432",
    username: NSUserName(),
    password: nil,
    database: "example"
)

let dbConnection = try await PostgresConnection.connect(
    configuration: dbConfig,
    id: 1,
    logger: logger
)

try await dbConnection.query(
    """
    CREATE OR REPLACE TRIGGER ...
    """,
    logger: logger
)

for try await _ in try await dbConnection.listen("example") {
    let rows = try await dbConnection.query(
        "SELECT ...",
        logger: logger
    )
}

The compiler reports:

.../Sources/main.swift:20:24: warning: result of call to 'query(_:logger:file:line:)' is unused
try await dbConnection.query(
                       ^    ~
.../Sources/main.swift:20:5: warning: no 'async' operations occur within 'await' expression
try await dbConnection.query(
    ^
.../Sources/main.swift:20:1: warning: no calls to throwing functions occur within 'try' expression
try await dbConnection.query(
^
.../Sources/main.swift:30:20: warning: no 'async' operations occur within 'await' expression
    let rows = try await dbConnection.query(
                   ^
.../Sources/main.swift:30:16: warning: no calls to throwing functions occur within 'try' expression
    let rows = try await dbConnection.query(
               ^
.../Sources/main.swift:30:9: warning: initialization of immutable value 'rows' was never used; consider replacing with assignment to '_' or removing it
    let rows = try await dbConnection.query(
    ~~~~^~~~
    _

My understanding (as a beginner) was that, per SE-0343, these top-level awaits should cause the top-level code to be interpreted as an async context, so why is Swift inferring the synchronous overloads of these functions?

Or am I misreading or drawing the wrong conclusions from these errors, and something else is going wrong?

2

Worth mentioning: the same code in a static func main() async throws works just fine.