Our team is also experiencing this - we use both Cocoapods (for now) and SPM and our local packages do this every time we switch branches. What works for me is closing the workspace before switching branches... which is annoying to say the least. Is there anything we can do to help get this fixed?
Package resolution log:
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Resolve Package Graph
Activity Log Complete 05/08/2020, 10:31 0.6 seconds
Build log:
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Prepare build
note: Using new build system
note: Building targets in parallel
note: Planning build
note: Using build description from memory
Build target <name> of project <name> with configuration Debug
error: Missing package product 'Deeplinks' (in target '<name>' from project '<name>')
error: Missing package product 'LocationProvider' (in target '<name>' from project '<name>')
error: Missing package product 'CountryCodes' (in target '<name>' from project '<name>')
error: Missing package product 'ReachabilityInternetProvider' (in target '<name>' from project '<name>')
error: Missing package product 'LanguageCodes' (in target '<name>' from project '<name>')
error: Missing package product 'BaggageDistributor' (in target '<name>' from project '<name>')
error: Missing package product 'ReachabilityInternetProvider' (in target '<name>' from project '<name>')
Build failed 05/08/2020, 10:31 0.2 seconds
This is on Xcode 11.6.