Difference between sync and install?

[berislavlopac]

I'm trying to understand what is (if any) the difference between pdm sync and pdm install? I was expecting sync to remove installed packages that are not in the lock file (e.g. if installed via pip), but apparently that is not the case.

[frostming]

They have some overlap, install even calls sync behind the scenes, but they both have some unique flags to do different jobs.

sync does remove unneeded packages if you pass --clean or --only-keep flag, which are not available for install command.

[stfdxv]

It's really surprising that pdm sync doesn't remove stray packages by default.
At the same time pdm remove some_package_added_via_pdm does remove stray packages.