Encountered error `Unimplemented` selecting <...> during codegen

[ckaran]

Update by pnkfelix: reduction to isolated test showing regression from 1.23.0 to 1.24.0 is given in comment below.

Original bug report follows

---

I'm using cargo-tarpaulin to ensure that my tests using proptest are covering all cases. In the process of testing this out, I ran into the following error:

$ reset ; RUSTC_BACKTRACE=1 ; cargo tarpaulin --force-clean -l -- --no-default-features
[INFO tarpaulin] Running Tarpaulin
[INFO tarpaulin] Building project
error: internal compiler error: src/librustc/traits/codegen/mod.rs:58: Encountered error `Unimplemented` selecting `Binder(<core::char::DecodeUtf16<<std::vec::Vec<u16> as core::iter::IntoIterator>::IntoIter> as arbitrary::traits::Arbitrary>)` during codegen

thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:595:9
note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
error: aborting due to previous error


note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.34.0-nightly (d17318011 2019-02-07) running on x86_64-unknown-linux-gnu

note: compiler flags: -C debuginfo=2 -C relocation-model=dynamic-no-pic -C link-dead-code -C opt-level=0 -C debuginfo=2 --crate-type lib

note: some of the compiler flags provided by cargo are hidden

[ERROR tarpaulin] Failed to compile tests! Error: build failed

EDIT A fairly small repository illustrating the bug can be found here.

Meta

rustc --version --verbose:

rustc 1.34.0-nightly (d17318011 2019-02-07)
binary: rustc
commit-hash: d1731801163df1d3a8d4ddfa68adac2ec833ef7f
commit-date: 2019-02-07
host: x86_64-unknown-linux-gnu
release: 1.34.0-nightly
LLVM version: 8.0

Backtrace

The only information that I got from the command is given above. If you know of better commands I can try to use, I can do so and amend this report.

[jethrogb]

Unable to reproduce, can't install tarpaulin:

error[E0599]: no method named `start` found for type `proc_macro2::Span` in the current scope
  --> /home/jethro/.cargo/registry/src/github.spider-man.dpdns.org-1ecc6299db9ec823/cargo-tarpaulin-0.7.0/src/source_analysis.rs:82:27
   |
82 |             for i in span.start().line..(span.end().line + 1) {
   |                           ^^^^^
   |
   = help: items from traits can only be used if the trait is implemented and in scope
   = note: the following trait defines an item `start`, perhaps you need to implement it:
           candidate #1: `statemachine::StateData`

[jethrogb]

If you are able to run it, can you run the command verbosely to extract the entire rustc command line? If you then run that command line yourself, does that also ICE?

[ckaran]

@jethrogb Here is what I have. Note that I ran git clean -xdf to get rid of all generated files before running any of these commands, so they are as clean as I can make them. If you want me to use some other commands, please give me the exact commands, and I can run them for you.

$ reset ; RUSTC_BACKTRACE=1 ; cargo tarpaulin --force-clean --line --verbose -- --no-default-features
[INFO tarpaulin] Running Tarpaulin
[DEBUG tarpaulin] Cleaning project
[INFO tarpaulin] Building project
warning: dependency (pyo3) specified without providing a local path, Git repository, or version to use. This will be considered an error in future versions
warning: unused manifest key: dependencies.pyo3.pyo3
    Updating crates.io index
   Compiling proc-macro2 v0.4.27                                                                                                                                                                                                       
   Compiling memchr v2.2.0                                                                                                                                                                                                             
   Compiling autocfg v0.1.2                                                                                                                                                                                                            
   Compiling libc v0.2.50                                                                                                                                                                                                              
   Compiling spin v0.5.0                                                                                                                                                                                                               
   Compiling rand_core v0.4.0                                                                                                                                                                                                          
   Compiling unicode-xid v0.1.0                                                                                                                                                                                                        
   Compiling regex v1.1.2                                                                                                                                                                                                              
   Compiling ucd-util v0.1.3                                                                                                                                                                                                           
   Compiling utf8-ranges v1.0.2                                                                                                                                                                                                        
   Compiling proc-macro-hack-impl v0.4.1                                                                                                                                                                                               
   Compiling cfg-if v0.1.7                                                                                                                                                                                                             
   Compiling version_check v0.1.5                                                                                                                                                                                                      
   Compiling byteorder v1.3.1                                                                                                                                                                                                          
   Compiling remove_dir_all v0.5.1                                                                                                                                                                                                     
   Compiling num-traits v0.2.6                                                                                                                                                                                                         
   Compiling fnv v1.0.6                                                                                                                                                                                                                
   Compiling quick-error v1.2.2                                                                                                                                                                                                        
   Compiling bit-vec v0.5.0                                                                                                                                                                                                            
   Compiling bitflags v1.0.4                                                                                                                                                                                                           
   Compiling rand_pcg v0.1.2                                                                                                                                                                                                           
   Compiling rand_chacha v0.1.1                                                                                                                                                                                                        
   Compiling rand v0.6.5                                                                                                                                                                                                               
   Compiling lazy_static v1.3.0                                                                                                                                                                                                        
   Compiling rand_core v0.3.1                                                                                                                                                                                                          
   Compiling rand_jitter v0.1.3                                                                                                                                                                                                        
   Compiling regex-syntax v0.6.5                                                                                                                                                                                                       
   Compiling proc-macro-hack v0.4.1                                                                                                                                                                                                    
   Compiling bit-set v0.5.0                                                                                                                                                                                                            
   Compiling rand_xorshift v0.1.1                                                                                                                                                                                                      
   Compiling rand_isaac v0.1.1                                                                                                                                                                                                         
   Compiling rand_hc v0.1.0                                                                                                                                                                                                            
   Compiling thread_local v0.3.6                                                                                                                                                                                                       
   Compiling rand_os v0.1.3                                                                                                                                                                                                            
   Compiling wait-timeout v0.1.5                                                                                                                                                                                                       
   Compiling quote v0.6.11                                                                                                                                                                                                             
   Compiling mashup-impl v0.1.9                                                                                                                                                                                                        
   Compiling aho-corasick v0.6.10                                                                                                                                                                                                      
   Compiling syn v0.15.27                                                                                                                                                                                                              
   Compiling mashup v0.1.9                                                                                                                                                                                                             
   Compiling tempfile v3.0.7                                                                                                                                                                                                           
   Compiling rusty-fork v0.2.1                                                                                                                                                                                                         
   Compiling proptest v0.9.1                                                                                                                                                                                                           
   Compiling pyo3 v0.6.0-alpha.4                                                                                                                                                                                                       
error: internal compiler error: src/librustc/traits/codegen/mod.rs:58: Encountered error `Unimplemented` selecting `Binder(<core::char::DecodeUtf16<<std::vec::Vec<u16> as core::iter::IntoIterator>::IntoIter> as arbitrary::traits::Arbitrary>)` during codegen
                                                                                                                                                                                                                                       
thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:620:9                                                                                                                                                                
note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.                                                                                                                                                         
error: aborting due to previous error                                                                                                                                                                                                  
                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                       
note: the compiler unexpectedly panicked. this is a bug.                                                                                                                                                                               
                                                                                                                                                                                                                                       
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports                                                                                                                      
                                                                                                                                                                                                                                       
note: rustc 1.35.0-nightly (a9da8fc9c 2019-03-04) running on x86_64-unknown-linux-gnu                                                                                                                                                  
                                                                                                                                                                                                                                       
note: compiler flags: -C debuginfo=2 -C relocation-model=dynamic-no-pic -C link-dead-code -C opt-level=0 -C debuginfo=2 --crate-type lib                                                                                               
                                                                                                                                                                                                                                       
note: some of the compiler flags provided by cargo are hidden                                                                                                                                                                          
                                                                                                                                                                                                                                       
error: Could not compile `proptest`.                                                                                                                                                                                                   
warning: build failed, waiting for other jobs to finish...
[ERROR tarpaulin] Failed to compile tests! Error: build failed 

Meta

$ rustc --version --verbose
rustc 1.35.0-nightly (a9da8fc9c 2019-03-04)
binary: rustc
commit-hash: a9da8fc9c267c08cfdb8cf5b39da14f154d12939
commit-date: 2019-03-04
host: x86_64-unknown-linux-gnu
release: 1.35.0-nightly
LLVM version: 8.0

$ uname -a
Linux EMANE 4.15.0-45-generic #48-Ubuntu SMP Tue Jan 29 16:28:13 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

$ lsb_release --all
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 18.04.2 LTS
Release:	18.04
Codename:	bionic

[jethrogb]

@ckaran I was hoping running tarpaulin verbosely would provide some more info, but unfortunately it doesn't really... Can you provide instructions on how to reproduce (including tarpaulin install) on a clean system, or docker container, or something like that?

[ckaran]

@jethrogb Did you get my last comment? I did as you asked yesterday, adding it as a comment, along with a ridiculously long copied chunk of standard out from re-running tarpaulin (it turns out you need to set RUST_LOG=trace to get output from tarpaulin), but I don't see the comment here any more. I'm hoping that this is just something temporary with GitHub; if not, let me know, and I can re-run everything and make it a part of my repository so you can see exactly what I did.

[jethrogb]

@ckaran no I got nothing. Sounds like GitHub ate your comment unfortunately.

[ckaran]

@jethrogb OK, I don't have time at the moment, but I'll work on putting something together in my repo that outlines shows what I'm seeing. RUST_LOG=trace generates an absolutely enormous amount of output, but I think that without doing that, you won't be able to see what I'm seeing, so that is what I'll do.

[ckaran]

@jethrogb I've updated the repository at https://github.com/ckaran/rustc_issue_report_58375 with the output from RUST_LOG=trace RUST_BACKTRACE=full cargo tarpaulin >> build_output.txt 2>&1. The resulting output is quite verbose; I hope that it will be of help to you. More details can be found in the update second of the README.md for the repository.

If that still doesn't work for you, everything I've done is within a virtual machine; as soon as I can figure out how to get a ~13 GB file to you, I could send it to you so you could play around with it and see what I'm seeing.

[jethrogb]

Can you run it again but with strace?

strace -etrace=execve -s 10000 -v -f cargo tarpaulin >> build_output.txt 2>&1

[ckaran]

@jethrogb Done. Pull the latest commit from the repository. Thank you for looking into this!

[jethrogb]

Reproduced by doing

RUSTFLAGS="-C relocation-model=dynamic-no-pic -C link-dead-code -C opt-level=0 -C debuginfo=2" cargo +nightly build --features bit-set,break-dead-code,byteorder,default,fork,num-traits,quick-error,rand,regex-syntax,rusty-fork,std,tempfile,timeout

in crate proptest version 0.9.1

[jethrogb]

possible dupe of #57131 or #52478