The some tests have the following expectation, or equivalent:

try #require(sync.wait(timeout: .now() + .seconds(2)) == .success)

This test is prone to flaky behaviour as the 2-second "timer" may or may not be sufficient.

We should update these affected tests to have a more deterministic assertion that does not rely on "timing" or any other behaviour that may cause a flaky tests.

Some suggestions:

• Perhaps Removing the timeout value all-together altogether and specifying a test-level timeout
• Getting away from that synchronous .wait call, and instead using something asynchronous

At the time of writing, the tests were:

• BasicsTests.ConcurrencyHelpersTest/threadSafeArrayStore()
• BasicsTests.ConcurrencyHelpersTest/threadSafeBox()
• BasicsTests.ConcurrencyHelpersTest/threadSafeKeyValueStore()
• CommandsTests.RunCommandTests/swiftRunSIGINT(buildSystem:)