Reproduction steps:

1. Open Unity
2. Click "New"
3. Create a New Project
4. "File" -> "New Project..."

Expected Result: Step 2 and 4 execute withing a reasonable amount of time (Less than 10 seconds)
Actual Result: Step 2 and 4 take an unreasonable amount of time (10+ seconds)

Reproduced with: 2018.2.0b1, 2018.1.0f1, 2017.4.1f1, 2017.3.2f1, 2017.2.2p3, 2017.1.3p3

Note:
Reproduces only on Mac 10.13 (Tested on 10.13.3)
Step 2 takes anywhere from 10 seconds to 1 minute. If you close the Launcher after step 2 and repeat, sometimes it never opens the new window to create the project.
Step 4 takes anywhere from 20 seconds to 1 minute and 20 seconds.