@diazona @filippo
Thanks for the explanation! I'd heard of configuring a package manager to require a specific dependency package version, but I hadn't heard it called locking, or using a specific file to store exclusively that information. The only times I've used such functionality, the required versions were stored in a general configuration file with a lot of other configuration management settings.

@diazona @filippo
But for your question, being "in xxx" where "xxx" is a package name suggests to me that they're trying to describe having the current working directory be either the package's source code directory, or the package's nstallation directory.

@diazona @filippo
I don't understand why such a thing would be called a lockfile. I've only ever heard "lockfile" used to mean a file that is temporarily created to indicate that some resource should be considered "locked", and unavailable for use by e.g. another process running the same or a related program. In other words, using the filesystem to implement a mutex. (This method only works for programs that agree to the usage convention; the OS kernel doesn't enforce anything.)