Document ExplainWhyBuildCommandsAreRun and add it to Xcode's preferences

Originator:keithbsmiley
Number:rdar://27516128 Date Originated:24-Jul-2016 12:50
Status:Open Resolved:
Product:Developer Tools Product Version:Xcode 8 beta 3
Classification:UI/Usability Reproducible:Always
 
Summary:
If you run this defaults command:

```
defaults write com.apple.dt.Xcode ExplainWhyBuildCommandsAreRun -bool YES
```

Xcode's build output will include detailed information on why specific commands were run. This output can be extremely useful for figuring out why compile times are slow, or just in general more information on how the build pipeline works. It would be great if this was a public Xcode preference.

Steps to Reproduce:
1) Try to find something on the internet about `ExplainWhyBuildCommandsAreRun`

Expected Results:
This option is documented somewhere, and is in Xcode's preferences.

Actual Results:
You find this tweet https://twitter.com/bdash/status/661742266487205888

Version:
Xcode 8 beta 3

Notes:

Comments


Please note: Reports posted here will not necessarily be seen by Apple. All problems should be submitted at bugreport.apple.com before they are posted here. Please only post information for Radars that you have filed yourself, and please do not include Apple confidential information in your posts. Thank you!