I added a Run Script build phase to my Xcode project, the script is just
echo \"Hello\"
I\'m not seing hello in the debug console or anyth
The quickest way that I found is by using the below echo command in my Run Script with "warning:" in it. Xcode threw a warining. Hence confirmed your script is getting executed
echo "warning: RUN SCRIPT in ACTION"
you also can try echo "error: RUN SCRIPT in ACTION"
In Xcode 6: View -> Navigators -> Show Report Navigator
On the left column, Under the By Group tab, select the latest Build for whatever target you just built.
In the middle column, select the All Messages tab, the output of your build script should be somewhere in there.
Xcode: View > Navigators > Show Report Navigator
The Report Navigator is the "chat bubble" in the Xcode sidebar.
Select your most recent Build from the sidebar on the left.
Then click All Messages in the tab bar to see the output of your Run Script Build Phase.

Legacy Xcode Versions:
Xcode 6+View > Navigators > Show Report Navigator
Xcode 5: View > Navigators > Show Log Navigator
Xcode 4: View > Navigators > View Log Navigator
You will see the output in the build log.
After build is successful, go to "View -> Navigators -> Show Report Navigator" (cmd+8) and check the latest log.