I'm building on postmarketOS 21.06 from the alpine packaged rust and I get the following error while compiling vgmms:

Compiling vgmms v0.1.0 (/home/user/src/vgmms) error[E0658]: or-patterns syntax is experimental --> src/chat_log.rs:131:9 | 131 | Some(MessageArea::Whitespace | MessageArea::Time() | MessageArea::Sender | MessageArea::Separator()) => return None, | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: see issue #54883 https://github.com/rust-lang/rust/issues/54883 for more information

error: aborting due to previous error

For more information about this error, try rustc --explain E0658. error: could not compile vgmms

I went into the chat_log.rs file and split that line into four, like this, which fixed it for me. Some(MessageArea::Whitespace) => return None, Some(MessageArea::Time()) => return None, Some(MessageArea::Sender) => return None,
Some(MessageArea::Separator()) => return None,

Not sure if you want to persist this change in your codebase but just letting you know it's an issue for people without experimental.