agvtool Error
I ran into this error from agvtool recently, and hope this might save someone a few minutes of frustration in the future.
If you have your INFOPLIST_FILE build setting value set to something like
$(SRCROOT)/MyApp/Info.plist and you run agvtool bump -all it will complain
Cannot find "$(SRCROOT)/MyApp/Info.plist".
The reason is that agvtool doesn’t understand the $(SRCROOT) variable.  So,
to fix this, you just have to remove that from the path – so, it becomes
MyApp/Info.plist in this case.  Xcode interprets it relative to $(SRCROOT)
anyway, so it will continue to work there, and now agvtool is happy.