I can't speak for Poetry directly, but knowing how Python dependency resolution works: I don't think Poetry can make lockfiles not platform-specific, since package source distributions are allowed to (and regularly do) run platform-specific code for their own dependency selection logic.

For example, your package might depend on `foo`, which in turn could sniff the host OS and select the appropriate subdependency. You'd then end up pinning that subdependency, which would be incorrect on a different host OS.

(Similarly for Python versions: a subdependency might be required on < 3.7, so re-installing from a lockfile generated from an older Python could produce a spurious runtime dependency.)