Misreported option::get failure

[jdm]

fn main() {
    let x = 5;
    #error("%?", x);
}

built with -g currently triggers an option::get failure in debuginfo::create_function. However, the only output is this:

godot:src jdm$ RUST_LOG=rustc=0,::rt::backtrace rust/build/x86_64-apple-darwin/stage2/bin/rustc -g rust_dbg2.rs 
rust: upcall fail 'option none', ../src/rustc/rustc.rc:1
error: internal compiler error unexpected failure
note: The compiler hit an unexpected failure path. This is a bug. Try running with RUST_LOG=rustc=0,::rt::backtrace to get further details and report the results to github.com/mozilla/rust/issues
rust: upcall fail 'explicit failure', ../src/rustc/driver/rustc.rs:180
rust: domain main @0x10302d200 root task failed

[marijnh]

This is a symptom of #2012.

[jdm]

I've fixed the actual cause of the failure, but it's the misreporting of it that I wanted this issue to address.

[marijnh]

I don't quite get it. Why do you think it's misreporting it? option::get fails with that message when you call it on none.

[jdm]

first of all - the upcall fail message 'option none' doesn't appear unless RUST_LOG includes ::rt::backtrace. Secondly, ../src/rustc/rustc.rc:1 is not the source of the failure. If you just run the compiler without any RUST_LOG, you see:

error: internal compiler error unexpected failure
note: The compiler hit an unexpected failure path. This is a bug. Try running with RUST_LOG=rustc=0,::rt::backtrace to get further details and report the results to github.com/mozilla/rust/issues

and nothing more.

[marijnh]

Ah, I see. The bad span info is bug #1972 , and the suppressing of fail messages is discussed in #1928 .