iron-gdc error about examples

[jimblandy]

Can I see your Cargo.toml file? I'm curious which version of the mime crate you're using.

[simoneromano96]

I left mime = * thinking it would select the latest version and evidently, it selected the first available version. Using the latest exact version made the program compile and work as expected. I read more about cargo in the Rust's documentation; if I understood right cargo will select automatically the latest version available if there are no major changes since the version specified in the .toml file, right?
Sorry for bringing this false problem up.
Thank you for the good book

[jimblandy]

You're welcome!

The '*' version number says that any version will do, including major version upgrades. Cargo will choose the newest available, and then stick with that version until you run cargo update.

In this case, the newest version of the mime crate is currently 0.3.5. As of 0.3.0, the mime crate no longer exports a mime! macro. Page 186 explains the rules for version numbers starting with zero; in short, 0.3.5 is not compatible with 0.2.3, as you discovered.