Long diagnostic for E0538

[Havvy]

r? @GuillaumeGomez

[rust-highfive]

The job x86_64-gnu-llvm-3.9 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[01:23:59] ---- /checkout/obj/build/x86_64-unknown-linux-gnu/test/error-index.md - Rust_Compiler_Error_Index::E0538 (line 9384) stdout ----
[01:23:59] error: unexpected token: `,`
[01:23:59]  --> /checkout/obj/build/x86_64-unknown-linux-gnu/test/error-index.md:9386:19
[01:23:59]   |
[01:23:59] 4 |     since="1.0.0"),
[01:23:59]   |                   ^ unexpected token after this
[01:23:59] 
[01:23:59] thread '/checkout/obj/build/x86_64-unknown-linux-gnu/test/error-index.md - Rust_Compiler_Error_Index::E0538 (line 9384)' panicked at 'Some expected error codes were not found: ["E0538"]', librustdoc/test.rs:330:13
[01:23:59] 
[01:23:59] ---- /checkout/obj/build/x86_64-unknown-linux-gnu/test/error-index.md - Rust_Compiler_Error_Index::E0538 (line 9400) stdout ----
[01:23:59] error: unexpected token: `,`
[01:23:59]  --> /checkout/obj/build/x86_64-unknown-linux-gnu/test/error-index.md:9402:19
[01:23:59]  --> /checkout/obj/build/x86_64-unknown-linux-gnu/test/error-index.md:9402:19
[01:23:59]   |
[01:23:59] 4 |     since="1.0.0"),
[01:23:59]   |                   ^ unexpected token after this
[01:23:59] thread '/checkout/obj/build/x86_64-unknown-linux-gnu/test/error-index.md - Rust_Compiler_Error_Index::E0538 (line 9400)' panicked at 'couldn't compile the test', librustdoc/test.rs:325:17
[01:23:59] 
[01:23:59] 
[01:23:59] failures:
---
[01:23:59] 
[01:23:59] 
[01:23:59] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[01:23:59] Build completed unsuccessfully in 0:41:19
[01:23:59] make: *** [check] Error 1
[01:23:59] Makefile:58: recipe for target 'check' failed

The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:0cb4f3bb
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[GuillaumeGomez]

What about "Attribute contains same meta item more than once"? (it's a real question, I'm not an english native so it's just a suggestion!)

[Havvy]

That is slightly better wording.

[GuillaumeGomez]

I'd like to have an english native's opinion on my suggestion, but otherwise, it looks good for me. Good job! :)

[GuillaumeGomez]

Then let's go for it!

@bors: r+ rollup

[bors]

📌 Commit e9e0ca0 has been approved by GuillaumeGomez