How to repro:
1. Open a new project using a Mac
2. Install the Android Logcat package
3. Open the Android Logcat window (Window -> Analysis -> Android Logcat)
4. Go to the terminal and type in this command, which will report how many PIPE type file handles are open by Unity:

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lsof -c Unity | egrep "PIPE" | awk '{ print $1; }'| sort -rn | uniq -c | sort -rn | head -20

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Expected Results: The number next to Unity should remain stable
Actual Results: The number next to Unity is increasing, while Logcat package is opened and there's no Android devices connected.