Function phase_embed_files 

pub fn phase_embed_files(
    parsed: &[ParsedFile],
    available: Option<&BTreeSet<String>>,
    errors: &mut ErrorSink,
)

bynk.embed.missing_file for each embed whose (otherwise valid) path names no file in available — the project’s embeds/ folder as the caller read it. None skips the check: nothing on disk was consulted (an in-memory check). A build passes Some, an empty set when it had no filesystem, so it never invents text for a file nobody read.

A path that already fails path_errors is not also reported missing.