Add treat-err-as-bug flag in rustdoc

[GuillaumeGomez]

cc @nikomatsakis
r? @QuietMisdreavus

[QuietMisdreavus]

Thanks for turning this around so quickly! r=me if travis is green.

[rust-highfive]

The job x86_64-gnu-llvm-5.0 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.

[01:26:47] 
[01:26:47] travis_fold:start:test_run-make
travis_time:start:test_run-make
Check compiletest suite=run-make mode=run-make (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
g" "--error-format=human" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/rustdoc-ui/treat-err-as-bug/auxiliary"
[01:26:48] ------------------------------------------
[01:26:48] 
[01:26:48] ------------------------------------------
[01:26:48] stderr:
---
[01:26:48]    |              - ^
[01:26:48]    |              |
[01:26:48]    |              un-closed delimiter
[01:26:48] 
[01:26:48] thread '<unnamed>' panicked at 'encountered error with `-Z treat_err_as_bug', librustc_errors/lib.rs:486:13
[01:26:48] 
[01:26:48] error: internal compiler error: unexpected panic
[01:26:48] 
[01:26:48] note: the compiler unexpectedly panicked. this is a bug.
[01:26:48] note: the compiler unexpectedly panicked. this is a bug.
[01:26:48] 
[01:26:48] note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
[01:26:48] 
[01:26:48] note: rustc 1.30.0-dev running on x86_64-unknown-linux-gnu
[01:26:48] 
[01:26:48] note: compiler flags: -Z ui-testing -Z unstable-options -Z treat-err-as-bug
[01:26:48] 
[01:26:48] ------------------------------------------
[01:26:48] 
[01:26:48] thread '[ui] rustdoc-ui/treat-err-as-bug.rs' panicked at 'explicit panic', tools/compiletest/src/runtest.rs:3205:9
---
[01:26:48] test result: FAILED. 6 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out
[01:26:48] 
[01:26:48] 
[01:26:48] 
[01:26:48] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/compiletest" "--compile-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib" "--run-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib" "--rustc-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "--rustdoc-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustdoc" "--src-base" "/checkout/src/test/rustdoc-ui" "--build-base" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/rustdoc-ui" "--stage-id" "stage2-x86_64-unknown-linux-gnu" "--mode" "ui" "--target" "x86_64-unknown-linux-gnu" "--host" "x86_64-unknown-linux-gnu" "--llvm-filecheck" "/usr/lib/llvm-5.0/bin/FileCheck" "--host-rustcflags" "-Zunstable-options " "--target-rustcflags" "-Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--docck-python" "/usr/bin/python2.7" "--lldb-python" "/usr/bin/python2.7" "--gdb" "/usr/bin/gdb" "--quiet" "--llvm-version" "5.0.0\n" "--system-llvm" "--cc" "" "--cxx" "" "--cflags" "" "--llvm-components" "" "--llvm-cxxflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always"
[01:26:48] 
[01:26:48] 
[01:26:48] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[01:26:48] Buil

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)

[QuietMisdreavus]

[01:26:48] ---- [ui] rustdoc-ui/treat-err-as-bug.rs stdout ----
[01:26:48] diff of stderr:
[01:26:48] 
[01:26:48] 15	
[01:26:48] 16	note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
[01:26:48] 17	
[01:26:48] -	note: rustc 1.30.0-dev running on x86_64-apple-darwin
[01:26:48] +	note: rustc 1.30.0-dev running on x86_64-unknown-linux-gnu
[01:26:48] 19	
[01:26:48] 20	note: compiler flags: -Z ui-testing -Z unstable-options -Z treat-err-as-bug
[01:26:48] 21	
[01:26:48] 
[01:26:48] 
[01:26:48] The actual stderr differed from the expected stderr.
[01:26:48] Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/rustdoc-ui/treat-err-as-bug/treat-err-as-bug.stderr
[01:26:48] To update references, rerun the tests and pass the `--bless` flag
[01:26:48] To only update this specific test, also pass `--test-args treat-err-as-bug.rs`
[01:26:48] 
[01:26:48] error: 1 errors occurred comparing output.
[01:26:48] status: exit code: 1

...i don't think this will work out. >_> I'm not totally sure what to do now. We can't wedge it into src/test/run-make-fulldeps/exit-code because it looks like the exit code is still 1 instead of 101 like it is for the compiler.

[GuillaumeGomez]

Well, I think we found out why there is no tests for this flag! 😆

[GuillaumeGomez]

I removed the test (but kept it in the history).

[QuietMisdreavus]

Welp, i guess we can just get this in now.

@bors r+

[bors]

📌 Commit 818938f has been approved by QuietMisdreavus