What does it mean for a package version to be incompatible?

[kyle-leonhard]

Love the tool! When running cargo upgrade I often see a warning like: Re-run with --incompatible to upgrade incompatible version requirements, and I see mention of version incompatibility and --incompatible in the readme and several issues (e.g. rust-lang/cargo#12425). However, I haven't found a definition of why a version might be incompatible. i thought, maybe it was any upgrades that weren't just patch version changes, but then, without --incompatible set, I see upgrades applied like: uuid 1.10.0 1.11.0 1.11.0 1.11.0.

What does "incompatible" actually mean in this context?

Here's a sample incompatibility I ran into today:

metrics                     0.23    0.23.0     0.24.0 0.23    incompatible
metrics-exporter-prometheus 0.15    0.15.3     0.16.0 0.15    incompatible

[epage]

There is already a discussion about this in #897 so closing in favor of that.

[kyle-leonhard]

Thanks @epage !