Errors inside macros use unreliable line/column references

[jdm]

Example:

a2q2a.rs:5:41: 5:47 error: unresolved modulename: std
a2q2a.rs:5         log_err #fmt("usage: %s infile", args[0]);
                                                    ^~~~~~

[brson]

I don't know what the right solution for this is in general. In this case, #fmt is doing a pretty good job of identifying where the problem is, it just doesn't result in a very helpful error. Here args[0] ends up more or less being wrapped in std::extfmt::conv_str(...), and we haven't declared that we're using crate std.

For this specific problem syntax extensions will probably need to declare which crates they depend on at runtime so the compiler can catch this.

[brson]

And happy 1000th issue, Rust!

[brson]

Extensions have changed a lot in the last 10 months. The original example is too vague to test against the current codebase, so I'm going to close this. I do believe expanded macros have better error reporting now.