RLS "Failed to start language server"

[mqudsi]

I'm running master, LanguageClient-neovim, deoplete, and git

My minimal vim.rc:

"dein Scripts-----------------------------
if &compatible
	set nocompatible
endif

let g:python3_host_prog = systemlist("which python3")[0]
let g:loaded_python_provider = 1

set runtimepath+=$HOME/.config/nvim/dein/repos/github.com/Shougo/dein.vim
filetype off

if dein#load_state('$HOME/.config/nvim/dein/')
	call dein#begin('$HOME/.config/nvim/dein/')
	call dein#add('Shougo/dein.vim')

	call dein#add('Shougo/deoplete.nvim')
	call dein#add('autozimu/LanguageClient-neovim',
		\{'on_ft': ['rust']})
	call dein#add('rust-lang/rust.vim',
		\{'on_ft': ['rust']})

	" Required:
	call dein#end()
	call dein#save_state()
endif

" Required:
filetype plugin indent on

let $RUST_SRC_PATH = glob("$HOME/.rustup/toolchains/nightly*/lib/rustlib/src/rust/src")

let g:LanguageClient_serverCommands = {
    \ 'rust': ['rustup', 'run', 'nightly', 'rls'],
	\ 'javascript': ['/usr/local/lib/node_modules/javascript-typescript-langserver/lib/language-server-stdio.js'],
	\ 'typescript': ['/usr/local/lib/node_modules/javascript-typescript-langserver/lib/language-server-stdio.js'],
\ }

" Automatically start language servers.
let g:LanguageClient_autoStart = 1

Result of LanguageClient.log:

22:41:40 WARNING  no handler implemented for rustDocument_diagnosticsBegin
22:41:40 WARNING  register completion manager source failed. Error: NvimError(b'Error calling function.',)
22:41:41 WARNING  no handler implemented for rustDocument_diagnosticsEnd
22:41:55 INFO     textDocument/didChange
22:41:55 DEBUG     => {"jsonrpc":"2.0","method":"textDocument/didChange","params":{"contentChanges":[{"text":"extern crate abstract_ns;\nextern crate futures;\nextern crate getopts;\nextern crate ns_dns_tokio;\nextern crate rand;\nextern crate tokio_core;\nextern crate tokio_io;\n\nuse abstract_ns::Resolver;\nuse futures::{Future, Stream};\nuse futures::future;\nuse getopts::Options;\nuse ns_dns_tokio::DnsResolver;\nuse std::collections:\nuse std::env;\nuse tokio_core::net::UdpSocket;\nuse tokio_core::reactor::Core;\nuse tokio_io::{AsyncRead, io};\n\nstatic mut DEBUG: bool = false;\n\nfn print_usage(program: &str, opts: Options) {\n    let program_path = std::path::PathBuf::from(program);\n    let program_name = program_path.file_stem().unwrap().to_str().unwrap();\n    let brief = format!(\"Usage: {} [-b BIND_ADDR] -l LOCAL_PORT -h REMOTE_ADDR -r REMOTE_PORT\",\n                        program_name);\n    print!(\"{}\", opts.usage(&brief));\n}\n\nfn main() {\n    let args: Vec<String> = env::args().collect();\n    let program = args[0].clone();\n\n    let mut opts = Options::new();\n    opts.reqopt(\"l\",\n                \"local-port\",\n                \"The local port to which udpproxy should bind to\",\n                \"LOCAL_PORT\");\n    opts.reqopt(\"r\",\n                \"remote-port\",\n                \"The remote port to which UDP packets should be forwarded\",\n                \"REMOTE_PORT\");\n    opts.reqopt(\"h\",\n                \"host\",\n                \"The remote address to which packets will be forwarded\",\n                \"REMOTE_ADDR\");\n    opts.optopt(\"b\",\n                \"bind\",\n                \"The address on which to listen for incoming requests\",\n                \"BIND_ADDR\");\n    opts.optflag(\"d\", \"debug\", \"Enable debug mode\");\n\n    let matches = opts.parse(&args[1..])\n        .unwrap_or_else(|_| {\n            print_usage(&program, opts);\n            std::process::exit(-1);\n        });\n\n    unsafe {\n        DEBUG = matches.opt_present(\"d\");\n    }\n    let local_port: i32 = matches.opt_str(\"l\").unwrap().parse().unwrap();\n    let remote_port: i32 = matches.opt_str(\"r\").unwrap().parse().unwrap();\n    let remote_host = matches.opt_str(\"h\").unwrap();\n    let bind_addr = match matches.opt_str(\"b\") {\n        Some(addr) => addr,\n        None => \"127.0.0.1\".to_owned(),\n    };\n\n    forward(&bind_addr, local_port, &remote_host, remote_port);\n}\n\nfn debug(msg: String) {\n    let debug: bool;\n    unsafe {\n        debug = DEBUG;\n    }\n\n    if debug {\n        println!(\"{}\", msg);\n    }\n}\n\nfn forward(bind_ip: &str, local_port: i32, remote_host: &str, remote_port: i32) {\n    //this is the main event loop, powered by tokio core\n    let mut core = Core::new().unwrap();\n    let handle = core.handle();\n\n    //listen on the specified IP and port\n    let bind_addr = format!(\"{}:{}\", bind_ip, local_port);\n    let bind_sock = bind_addr.parse().unwrap();\n    let listener = UdpSocket::bind(&bind_sock, &handle)\n        .expect(&format!(\"Unable to bind to {}\", &bind_addr));\n    println!(\"Listening on {}\", listener.local_addr().unwrap());\n\n    //we have either been provided an IP address or a host name\n    //instead of trying to check its format, just trying creating a SocketAddr from it\n    let parse_result = format!(\"{}:{}\", remote_host, remote_port).parse::<std::net::SocketAddr>();\n    let server = future::result(parse_result)\n        .or_else(|_| {\n            //it's a hostname; we're going to need to resolve it\n            //create an async dns resolver\n            let resolver = DnsResolver::system_config(&handle).unwrap();\n\n            resolver.resolve(&format!(\"{}:{}\", remote_host, remote_port))\n                .map(move |resolved| {\n                    resolved.pick_one()\n                        .expect(&format!(\"No valid IP addresses for target {}\", remote_host))\n                })\n                .map_err(|err| println!(\"{:?}\", err))\n        })\n        .and_then(|remote_addr| {\n            println!(\"Resolved {}:{} to {}\",\n                     remote_host,\n                     remote_port,\n                     remote_addr);\n\n            let remote_addr = remote_addr.clone();\n            let handle = handle.clone();\n            listener.incoming()\n                .for_each(move |(client, client_addr)| {\n                    println!(\"New connection from {}\", client_addr);\n\n                    //establish connection to upstream for each incoming client connection\n                    let handle = handle.clone();\n                    TcpStream::connect(&remote_addr, &handle).and_then(move |remote| {\n                        let (client_recv, client_send) = client.split();\n                        let (remote_recv, remote_send) = remote.split();\n\n                        let remote_bytes_copied = io::copy(remote_recv, client_send);\n                        let client_bytes_copied = io::copy(client_recv, remote_send);\n\n                        fn error_handler<T, V>(err: T, client_addr: V)\n                            where T: std::fmt::Debug,\n                                  V: std::fmt::Display\n                        {\n                            println!(\"Error writing from upstream server to remote client {}!\",\n                                     client_addr);\n                            println!(\"{:?}\", err);\n                            ()\n                        };\n\n                        let client_addr_clone = client_addr.clone();\n                        let async1 = remote_bytes_copied.map(move |(count, _, _)| {\n                                debug(format!(\"Transferred {} bytes from upstream server to \\\n                                               remote client {}\",\n                                              count,\n                                              client_addr_clone))\n                            })\n                            .map_err(move |err| error_handler(err, client_addr_clone));\n\n                        let client_addr_clone = client_addr;\n                        let async2 = client_bytes_copied.map(move |(count, _, _)| {\n                                debug(format!(\"Transferred {} bytes from remote client {} to \\\n                                               upstream server\",\n                                              count,\n                                              client_addr_clone))\n                            })\n                            .map_err(move |err| error_handler(err, client_addr_clone));\n\n                        handle.spawn(async1);\n                        handle.spawn(async2);\n\n                        Ok(())\n                    })\n                })\n                .map_err(|err| println!(\"{:?}\", err))\n        });\n\n    core.run(server).unwrap();\n}\n"}],"textDocument":{"version":2,"uri":"file:///mnt/d/GIT/udpproxy/src/main.rs"}}}
22:41:55 DEBUG     <= {"jsonrpc":"2.0","method":"rustDocument/diagnosticsBegin","params":null}
22:41:55 WARNING  no handler implemented for rustDocument_diagnosticsBegin
22:41:56 INFO     textDocument/didChange
22:41:56 DEBUG     => {"jsonrpc":"2.0","method":"textDocument/didChange","params":{"contentChanges":[{"text":"extern crate abstract_ns;\nextern crate futures;\nextern crate getopts;\nextern crate ns_dns_tokio;\nextern crate rand;\nextern crate tokio_core;\nextern crate tokio_io;\n\nuse abstract_ns::Resolver;\nuse futures::{Future, Stream};\nuse futures::future;\nuse getopts::Options;\nuse ns_dns_tokio::DnsResolver;\nuse std::collections::\nuse std::env;\nuse tokio_core::net::UdpSocket;\nuse tokio_core::reactor::Core;\nuse tokio_io::{AsyncRead, io};\n\nstatic mut DEBUG: bool = false;\n\nfn print_usage(program: &str, opts: Options) {\n    let program_path = std::path::PathBuf::from(program);\n    let program_name = program_path.file_stem().unwrap().to_str().unwrap();\n    let brief = format!(\"Usage: {} [-b BIND_ADDR] -l LOCAL_PORT -h REMOTE_ADDR -r REMOTE_PORT\",\n                        program_name);\n    print!(\"{}\", opts.usage(&brief));\n}\n\nfn main() {\n    let args: Vec<String> = env::args().collect();\n    let program = args[0].clone();\n\n    let mut opts = Options::new();\n    opts.reqopt(\"l\",\n                \"local-port\",\n                \"The local port to which udpproxy should bind to\",\n                \"LOCAL_PORT\");\n    opts.reqopt(\"r\",\n                \"remote-port\",\n                \"The remote port to which UDP packets should be forwarded\",\n                \"REMOTE_PORT\");\n    opts.reqopt(\"h\",\n                \"host\",\n                \"The remote address to which packets will be forwarded\",\n                \"REMOTE_ADDR\");\n    opts.optopt(\"b\",\n                \"bind\",\n                \"The address on which to listen for incoming requests\",\n                \"BIND_ADDR\");\n    opts.optflag(\"d\", \"debug\", \"Enable debug mode\");\n\n    let matches = opts.parse(&args[1..])\n        .unwrap_or_else(|_| {\n            print_usage(&program, opts);\n            std::process::exit(-1);\n        });\n\n    unsafe {\n        DEBUG = matches.opt_present(\"d\");\n    }\n    let local_port: i32 = matches.opt_str(\"l\").unwrap().parse().unwrap();\n    let remote_port: i32 = matches.opt_str(\"r\").unwrap().parse().unwrap();\n    let remote_host = matches.opt_str(\"h\").unwrap();\n    let bind_addr = match matches.opt_str(\"b\") {\n        Some(addr) => addr,\n        None => \"127.0.0.1\".to_owned(),\n    };\n\n    forward(&bind_addr, local_port, &remote_host, remote_port);\n}\n\nfn debug(msg: String) {\n    let debug: bool;\n    unsafe {\n        debug = DEBUG;\n    }\n\n    if debug {\n        println!(\"{}\", msg);\n    }\n}\n\nfn forward(bind_ip: &str, local_port: i32, remote_host: &str, remote_port: i32) {\n    //this is the main event loop, powered by tokio core\n    let mut core = Core::new().unwrap();\n    let handle = core.handle();\n\n    //listen on the specified IP and port\n    let bind_addr = format!(\"{}:{}\", bind_ip, local_port);\n    let bind_sock = bind_addr.parse().unwrap();\n    let listener = UdpSocket::bind(&bind_sock, &handle)\n        .expect(&format!(\"Unable to bind to {}\", &bind_addr));\n    println!(\"Listening on {}\", listener.local_addr().unwrap());\n\n    //we have either been provided an IP address or a host name\n    //instead of trying to check its format, just trying creating a SocketAddr from it\n    let parse_result = format!(\"{}:{}\", remote_host, remote_port).parse::<std::net::SocketAddr>();\n    let server = future::result(parse_result)\n        .or_else(|_| {\n            //it's a hostname; we're going to need to resolve it\n            //create an async dns resolver\n            let resolver = DnsResolver::system_config(&handle).unwrap();\n\n            resolver.resolve(&format!(\"{}:{}\", remote_host, remote_port))\n                .map(move |resolved| {\n                    resolved.pick_one()\n                        .expect(&format!(\"No valid IP addresses for target {}\", remote_host))\n                })\n                .map_err(|err| println!(\"{:?}\", err))\n        })\n        .and_then(|remote_addr| {\n            println!(\"Resolved {}:{} to {}\",\n                     remote_host,\n                     remote_port,\n                     remote_addr);\n\n            let remote_addr = remote_addr.clone();\n            let handle = handle.clone();\n            listener.incoming()\n                .for_each(move |(client, client_addr)| {\n                    println!(\"New connection from {}\", client_addr);\n\n                    //establish connection to upstream for each incoming client connection\n                    let handle = handle.clone();\n                    TcpStream::connect(&remote_addr, &handle).and_then(move |remote| {\n                        let (client_recv, client_send) = client.split();\n                        let (remote_recv, remote_send) = remote.split();\n\n                        let remote_bytes_copied = io::copy(remote_recv, client_send);\n                        let client_bytes_copied = io::copy(client_recv, remote_send);\n\n                        fn error_handler<T, V>(err: T, client_addr: V)\n                            where T: std::fmt::Debug,\n                                  V: std::fmt::Display\n                        {\n                            println!(\"Error writing from upstream server to remote client {}!\",\n                                     client_addr);\n                            println!(\"{:?}\", err);\n                            ()\n                        };\n\n                        let client_addr_clone = client_addr.clone();\n                        let async1 = remote_bytes_copied.map(move |(count, _, _)| {\n                                debug(format!(\"Transferred {} bytes from upstream server to \\\n                                               remote client {}\",\n                                              count,\n                                              client_addr_clone))\n                            })\n                            .map_err(move |err| error_handler(err, client_addr_clone));\n\n                        let client_addr_clone = client_addr;\n                        let async2 = client_bytes_copied.map(move |(count, _, _)| {\n                                debug(format!(\"Transferred {} bytes from remote client {} to \\\n                                               upstream server\",\n                                              count,\n                                              client_addr_clone))\n                            })\n                            .map_err(move |err| error_handler(err, client_addr_clone));\n\n                        handle.spawn(async1);\n                        handle.spawn(async2);\n\n                        Ok(())\n                    })\n                })\n                .map_err(|err| println!(\"{:?}\", err))\n        });\n\n    core.run(server).unwrap();\n}\n"}],"textDocument":{"version":3,"uri":"file:///mnt/d/GIT/udpproxy/src/main.rs"}}}
22:41:56 DEBUG     <= {"jsonrpc":"2.0","method":"rustDocument/diagnosticsBegin","params":null}
22:41:56 WARNING  no handler implemented for rustDocument_diagnosticsBegin
22:41:56 DEBUG     <= 
22:41:56 ERROR    Failed to start language server: [b'{"message":"expected identifier, found keyword `use`","code":null,"level":"error","spans":[{"file_name":"src/main.rs","byte_start":320,"byte_end":323,"line_start":15,"line_end":15,"column_start":1,"column_end":4,"is_primary":true,"text":[{"text":"use std::env;","highlight_start":1,"highlight_end":4}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":null}\n', b'{"message":"expected one of `::`, `;`, or `as`, found `std`","code":null,"level":"error","spans":[{"file_name":"src/main.rs","byte_start":323,"byte_end":323,"line_start":15,"line_end":15,"column_start":4,"column_end":4,"is_primary":false,"text":[{"text":"use std::env;","highlight_start":4,"highlight_end":4}],"label":"expected one of `::`, `;`, or `as` here","suggested_replacement":null,"expansion":null},{"file_name":"src/main.rs","byte_start":324,"byte_end":327,"line_start":15,"line_end":15,"column_start":5,"column_end":8,"is_primary":true,"text":[{"text":"use std::env;","highlight_start":5,"highlight_end":8}],"label":"unexpected token","suggested_replacement":null,"expansion":null}],"children":[],"rendered":null}\n', b'{"message":"aborting due to 2 previous errors","code":null,"level":"error","spans":[],"children":[],"rendered":null}\n', b'thread \'<unnamed>\' panicked at \'could not run cargo: CargoError(Internal(Msg("failed to stat `/mnt/d/GIT/udpproxy/target/rls/debug/.fingerprint/udpproxy-9ca18b3406e94519/dep-bin-udpproxy-9ca18b3406e94519`")), State { next_error: Some(Error { repr: Os { code: 2, message: "No such file or directory" } }), backtrace: None })\', /checkout/src/libcore/result.rs:860:4\n', b'note: Run with `RUST_BACKTRACE=1` for a backtrace.\n', b'thread \'<unnamed>\' panicked at \'called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"\', /checkout/src/libcore/result.rs:860:4\n', b'thread \'main\' panicked at \'called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"\', /checkout/src/libcore/result.rs:860:4\n']
22:41:57 ERROR    Failed to start language server: []
22:41:57 ERROR    Failed to start language server: []
22:41:59 ERROR    Failed to start language server: []

:CheckHealth:

health#deoplete#check
========================================================================
## deoplete.nvim
  - SUCCESS: has("nvim") was successful
  - SUCCESS: has("python3") was successful
  - INFO: If you're still having problems, try the following commands:
    $ export NVIM_PYTHON_LOG_FILE=/tmp/log
    $ export NVIM_PYTHON_LOG_LEVEL=DEBUG
    $ nvim
    $ cat /tmp/log_{PID}
    and then create an issue on github

health#nvim#check
========================================================================
## Configuration
  - SUCCESS: no issues found

## Performance
  - SUCCESS: Build type: RelWithDebInfo

## Remote Plugins
  - SUCCESS: Up to date

## terminal
  - INFO: key_backspace (kbs) terminfo entry: key_backspace=\177
  - INFO: key_dc (kdch1) terminfo entry: key_dc=\E[3~

health#provider#check
========================================================================
## Clipboard (optional)
  - SUCCESS: Clipboard tool found: win32yank

## Python 2 provider (optional)
  - INFO: Disabled. g:loaded_python_provider=1

## Python 3 provider (optional)
  - INFO: Using: g:python3_host_prog = "/usr/bin/python3"
  - INFO: Executable: /usr/bin/python3
  - INFO: Python3 version: 3.5.2
  - INFO: python3-neovim version: 0.1.13
  - SUCCESS: Latest python3-neovim is installed: 0.1.13

## Ruby provider (optional)
  - WARNING: `ruby` and `gem` must be in $PATH.
    - SUGGESTIONS:
      - Install Ruby and verify that `ruby` and `gem` commands work.

rplugin.vim:

" python3 plugins
call remote#host#RegisterPlugin('python3', '/home/mqudsi/.config/nvim/dein/.cache/init.vim/.dein/rplugin/python3/deoplete', [
      \ {'sync': v:false, 'name': '_deoplete', 'type': 'function', 'opts': {}},
     \ ])
call remote#host#RegisterPlugin('python3', '/home/mqudsi/.config/nvim/dein/repos/github.com/autozimu/LanguageClient-neovim/rplugin/python3/LanguageClient', [
      \ {'sync': v:true, 'name': 'LanguageClient_alive', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_completionItem/resolve', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_completionManager_refresh', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_exit', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_FZFSinkTextDocumentDocumentSymbol', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_FZFSinkTextDocumentReferences', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_FZFSinkWorkspaceSymbol', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'BufReadPost', 'type': 'autocmd', 'opts': {'pattern': '*'}},
      \ {'sync': v:false, 'name': 'CursorMoved', 'type': 'autocmd', 'opts': {'pattern': '*', 'eval': 'line(''.'')'}},
      \ {'sync': v:false, 'name': 'TextChanged', 'type': 'autocmd', 'opts': {'pattern': '*', 'eval': 'fnamemodify(expand("<afile>"), ":p")'}},
      \ {'sync': v:false, 'name': 'TextChangedI', 'type': 'autocmd', 'opts': {'pattern': '*', 'eval': 'fnamemodify(expand("<afile>"), ":p")'}},
      \ {'sync': v:false, 'name': 'VimEnter', 'type': 'autocmd', 'opts': {'pattern': '*'}},
      \ {'sync': v:false, 'name': 'LanguageClient_initialize', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_registerServerCommands', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_setLoggingLevel', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClientStart', 'type': 'command', 'opts': {'nargs': '*', 'range': ''}},
      \ {'sync': v:false, 'name': 'LanguageClientStop', 'type': 'command', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_textDocument_completion', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_textDocument_completionOmnifunc', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_textDocument_definition', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_textDocument_didClose', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'BufWritePost', 'type': 'autocmd', 'opts': {'pattern': '*'}},
      \ {'sync': v:false, 'name': 'LanguageClient_textDocument_documentSymbol', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_textDocument_formatting', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_textDocument_hover', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_textDocument_rangeFormatting', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_textDocument_references', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_textDocument_rename', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_textDocument_signatureHelp', 'type': 'function', 'opts': {}},
      \ {'sync': v:false, 'name': 'LanguageClient_workspace_symbol', 'type': 'function', 'opts': {}},
     \ ])


" ruby plugins


" python plugins

[autozimu]

I cannot help you much as the information doesn't make it clear what went wrong. But here is a few general trouble shooting tips:

• Make sure rls is running properly outside this plugin. Could verify it with official vscode extension.
• Use this project provided min vimrc. Follow this project provided trouble shooting steps.

[mqudsi]

I reported it upstream: rust-lang/rls#443

We'll see what happens.