`swift test` prints `error: fatalError` twice on build failure

[MaxDesiatov]

Description

In addition to an unhelpful error message it is printed twice when swift test fails to build a test target.

Expected behavior

An error message is printed saying that tests couldn't be run as they failed to build. The error message should be printed only once.

Actual behavior

error: fatalError message is printed twice.

Steps to reproduce

1. swift package init --type library
2. Open the automatically generated test case.
3. Add this code snippet to it:

    func testExample() throws {
        let x = 0
        let y = 1 / x
        print(y)
    }

4. Run swift test on the command line.

Swift Package Manager version/commit hash

Latest SwiftPM nightly from main

Swift & OS version (output of swift --version ; uname -a)

Swift development snapshot, macOS 13

[MaxDesiatov]

No longer reproducible with swift-DEVELOPMENT-SNAPSHOT-2024-10-08-a.