[OSX] Editor crashes on exporting and saving packages. Unity keeps hanging in processes and Bug Reporter is not called.

To repro:
1. Open Unity and create a new project.
2. Create one folder and e.g. script.
3. Right click on the script and select Export package...
4. Name it and save.

Actual result: Unity crashes.
Note: Sometimes Unity crashes on the second try after deselecting "Including dependencies" in Export window.

5 Unity 0x0000000100737a5c -[GlobalProgressbarController cleanup] + 140
6 Unity 0x000000010073234c ___Z32CompressTarGZAndDeleteFolderImplP8NSStringS0_S0_U13block_pointerFvvE_block_invoke + 364
7 Foundation 0x00007fff49e08dc8 __45-[NSConcreteTask launchWithDictionary:error:]_block_invoke_2 + 2

Expected result: Unity does not crash.

Regression since 2018.1.0b6.
Reproduces on
Version 2018.2.0a2 (eef84ef17bdd)
Wed, 21 Feb 2018 12:17:45 GMT
Branch: trunk