rustc can't read files with more than one dot in filename

[matthiaskrgr]

echo "pub fn main() {}" > a.b.rs
rustc a.b.rs

error: invalid character `'.'` in crate name: `a.b`

Why would rustc think this is related to crates when I just pass a simple path into it?

[ehuss]

Rustc has to infer the crate name when you don't specify it with --crate-name, or with #![crate_name="…"]. It is not as important for a binary compared to a library (since you can't directly import a binary), but it still appears in some circumstances like symbols, debuginfo, some diagnostics, and macros, and still needs to be well-formed.

[matthiaskrgr]

Hmm, so it assumes {crate_name}.rs which would in this case be "a.b" which is not a valid crate name?
It would be nice to have some help message for the a.b.rs case which hints to usage of either --crate-name or #![crate_name="…"] 🙂