More like "Where's the program?"
Early '80s Smalltalk did use change-sets in files.
p462 "Smalltalk-80 The Interactive Programming Environment"
https://rmod-files.lille.inria.fr/FreeBooks/TheInteractivePr...
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You're right, Smalltalk is about "modifying objects that represent classes and methods" rather than editing files.
So versioning means fine-grained "classes and methods" rather than versioning files.
https://www.google.com/books/edition/Mastering_ENVY_Develope...
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You're right, we know what we like - we like what we know.
So (Pharo) "Manage Your Code with Git and Iceberg"
https://books.pharo.org/booklet-ManageCode/pdf/2020-05-12-Ma...