I've seen this error in the past but it's come back. 😟
Here's what it spits out (redacted)
CodeSign ~/Library/Developer/Xcode/DerivedData/...BundleName.bundle
cd ~/.../Pods
export CODESIGN_ALLOCATE=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/codesign_allocate
export PATH="..."
Signing Identity: "-"
/usr/bin/codesign --force --sign - --timestamp=none ~/Library/Developer/Xcode/DerivedData/...BundleName.bundle
~/Library/Developer/Xcode/DerivedData/...BundleName.bundle: bundle format unrecognized, invalid, or unsuitable
Command /usr/bin/codesign failed with exit code 1
Have development pod with .bundle packages in the src. Those packages have directories named Resources. If we change it to anything else, the problem goes away.
Worked fine on Xcode 8.0