Open Radar

 
Summary:
In my project, when setting a custom class for a view in Interface Builder and keeping the default “Inherit Module From Target”, the app will crash like this:

2018-03-01 10:44:06.191809+0100 TargetName[75262:2191024] Unknown class _TtC7appname26TopContentViewWithoutGraph in Interface Builder file.
2018-03-01 10:44:06.259342+0100 TargetName[75262:2191024] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<UIView 0x7febc5e76670> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key buttonContainerHeightConstraint.'

To protect the client, I’ve renamed specific words. The module is called “APPName”, but in the compiled nib, it seems to be pointing to a symbol containing “appname”, which I think is what is causing the crash. The line that compiles the Nib looks like this:

CompileXIB Main/Views/TopContentViewWithoutGraph.xib
    cd /Users/simon/code/appname-ios/app
    export PATH="/Applications/Xcode/Xcode-9.2.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode/Xcode-9.2.app/Contents/Developer/usr/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin"
    export XCODE_DEVELOPER_USR_PATH=/Applications/Xcode/Xcode-9.2.app/Contents/Developer/usr/bin/..
    /Applications/Xcode/Xcode-9.2.app/Contents/Developer/usr/bin/ibtool --errors --warnings --notices --module appname --output-partial-info-plist /Users/simon/Library/Developer/Xcode/DerivedData/APPName-gojknyfwzriukldevdemryowfsoh/Build/Intermediates.noindex/APPName.build/Debug-iphonesimulator/Target\ Name.build/TopContentViewWithoutGraph-PartialInfo.plist --auto-activate-custom-fonts --target-device iphone --minimum-deployment-target 10.0 --output-format human-readable-text --compile /Users/simon/Library/Developer/Xcode/DerivedData/APPName-gojknyfwzriukldevdemryowfsoh/Build/Products/Debug-iphonesimulator/TargetName.app/TopContentViewWithoutGraph.nib /Users/simon/code/appname-ios/app/Main/Views/TopContentViewWithoutGraph.xib

As you see, there is a ‘—module appname’ there. In other calls to ibtool, like a storyboard, I see the correct ‘—module APPName’. 

Steps to Reproduce:
I was unable to reproduce this in a simple project.

Expected Results:
Pass the correct module name and don’t crash. 

Actual Results:
Pass wrong module name and crash. 

Version:
Version 9.2 (9C40b) 

Notes:
Workaround is to uncheck “Inherit module from target”, which fills in APPName for me explicitly and works.