1. What happened
Reproducible on OS X with new runtime only - doesn't happen on legacy Mono. Editor crashes, with no Bug Reporter being invoked after Visual Studio debugger gets attached and detached few times.

This is a regression from 2017.1.0p3

2. How we can reproduce it using the example you attached
- Attached is an empty project with 1 default script.
- Open script in VS
- Attach VS to the Editor with 'Play' debugger btn and wait few seconds (2-3)
- Stop the debugger and wait few seconds (2-3)
- Start
- Stop
- Start (overall - 3rd attempt. for me it always crashes at this moment)
>>> Crash. Only OSX crash reporter is invoked

Editor log ends with:
=================================================================
Got a SIGABRT while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries
used by your application.
=================================================================

Reproducible in 2017.2.0b7 and 2017.3.0a3.