I've encountered this on a recent PR: bazel-ios/rules_ios#246 . It seems like the simulator infrastructure is flaking, but writing a result bundle. Finally when it tries to re-launch, there's an existing result bundle so it can't retry. Note that this is ran inside of the sandbox ATM.
Please find the github action here:
https://github.com/bazel-ios/rules_ios/runs/2786242526
2021-06-09 17:47:48,662 Failed to launch test on simulator. Will relaunch again.
xcodebuild: error: Existing file at -resultBundlePath "/var/tmp/_bazel_runner/c2342bca25695567c8c3f3be166b56b3/sandbox/darwin-sandbox/1286/execroot/build_bazel_rules_ios/bazel-out/darwin-dbg/testlogs/tests/ios/unit-test/ExplicitHosted/test.outputs/test.xcresult"
2021-06-09 17:47:50,048 Failed to launch test on simulator. Will relaunch again.
xcodebuild: error: Existing file at -resultBundlePath "/var/tmp/_bazel_runner/c2342bca25695567c8c3f3be166b56b3/sandbox/darwin-sandbox/1286/execroot/build_bazel_rules_ios/bazel-out/darwin-dbg/testlogs/tests/ios/unit-test/ExplicitHosted/test.outputs/test.xcresult"