codesign failure in AppCode, but not Xcode

My AppCode builds fail with a codesign error.  The build works after a clean, but subsequent, incremental builds fail with the codesign error.  I have no problems building in Xcode 8.  The trouble seemed to start after I installed Xcode 8.  My AppCode version info and build log snippet are below.

AppCode 2016.3 EAP

Build #OC-163.5644.16, built on October 6, 2016
AppCode EAP User
Expiration date: November 5, 2016
JRE: 1.8.0_112-release-b408 x86_64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o

Build Log Snippet

CodeSign /Users/stjohnr/Library/Caches/AppCode2016.3/DerivedData/DICE-bsxbmnmnwjtxorfcorgdgsywpavi/Build/Products/Debug-iphonesimulator/DICE.app/PlugIns/DICETests.xctest
 cd /Users/stjohnr/sandbox/dice-ios
 export CODESIGN_ALLOCATE=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/codesign_allocate
 export PATH="/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/local/bin:/Users/stjohnr/.rvm/gems/ruby-2.1.5-latest/bin:/Users/stjohnr/.rvm/gems/ruby-2.1.5-latest@global/bin:/Users/stjohnr/.rvm/rubies/ruby-2.1.5-latest/bin:/Users/stjohnr/bin:/usr/local/go_appengine:/usr/local/android-ndk32:/usr/local/android-sdk/platform-tools:/usr/local/android-sdk/tools:/usr/local/bin:/usr/local/gradle/bin:/usr/local/opt/groovy/libexec/bin:/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin:/Users/stjohnr/.rvm/bin"
 
Signing Identity: "-"

/usr/bin/codesign --force --sign - --timestamp=none /Users/stjohnr/Library/Caches/AppCode2016.3/DerivedData/DICE-bsxbmnmnwjtxorfcorgdgsywpavi/Build/Products/Debug-iphonesimulator/DICE.app/PlugIns/DICETests.xctest
/Users/stjohnr/Library/Caches/AppCode2016.3/DerivedData/DICE-bsxbmnmnwjtxorfcorgdgsywpavi/Build/Products/Debug-iphonesimulator/DICE.app/PlugIns/DICETests.xctest: code object is not signed at all
In subcomponent: /Users/stjohnr/Library/Caches/AppCode2016.3/DerivedData/DICE-bsxbmnmnwjtxorfcorgdgsywpavi/Build/Products/Debug-iphonesimulator/DICE.app/PlugIns/DICETests.xctest/All in ReportStoreSpec.m.xctestconfiguration
Command /usr/bin/codesign failed with exit code 1

** BUILD FAILED **


The following build commands failed:
 CodeSign /Users/stjohnr/Library/Caches/AppCode2016.3/DerivedData/DICE-bsxbmnmnwjtxorfcorgdgsywpavi/Build/Products/Debug-iphonesimulator/DICE.app/PlugIns/DICETests.xctest
(1 failure)