Error: Invalid Value Object

[ImkoMarijnissen]

OS: WSL 2 - Ubuntu 22.04
VSCode version: 1.93.1
CodeLLDB version: 1.10.1
Compiler: rustc
Debuggee: x86_64-linux-gnu

While debugging, I ran into the issue that I cannot see the values of vectors as it simply shows that <error: invalid value object> with the following error output message:

Verbose log

[DEBUG codelldb::dap_codec] --> {"command":"evaluate","arguments":{"expression":"boolean","frameId":1001,"context":"watch"},"type":"request","seq":26}
ERROR(Python) 13:47:14 codelldb: Traceback (most recent call last):
  File "/home/user/.vscode-server/extensions/vadimcn.vscode-lldb-1.10.0/adapter/scripts/codelldb/codelldb.py", line 175, in evaluate
    value = evaluate_in_context(pycode, is_simple_expr, context)
  File "/home/user/.vscode-server/extensions/vadimcn.vscode-lldb-1.10.0/adapter/scripts/codelldb/codelldb.py", line 320, in evaluate_in_context
    return eval(code, eval_globals, eval_locals)
  File "", line 1, in 
  File "/home/user/.vscode-server/extensions/vadimcn.vscode-lldb-1.10.0/adapter/scripts/codelldb/codelldb.py", line 309, in 
    eval_globals['__eval'] = lambda expr: nat_eval(frame, expr)
  File "/home/user/.vscode-server/extensions/vadimcn.vscode-lldb-1.10.0/adapter/scripts/codelldb/codelldb.py", line 300, in nat_eval
    raise Exception(err.GetCString())
Exception: error: could not find item

[elenakrittik]

Same issue for me!

[joshuataylor]

Also seeing this on RustRover, seems rust-lang/rust#126793 changed lldb_providers.py , I'll see if I can submit an issue..

[liukaizheng]

Because Rust have changed the implementation of Vec by using RawVec, which is essentially an u8 array, not a T array. Codelldb cannot't currently infer the type T by it's customized rust formmater. It still doesn't work even though I use the formatter provided by lldb_providers.py

class StdVecSyntheticProvider:
    def __init__(self, valobj, dict):
        self.valobj = valobj
        self.update()

    def num_children(self):
        return self.length

    def get_child_index(self, name):
        index = name.lstrip('[').rstrip(']')
        if index.isdigit():
            return int(index)
        else:
            return -1

    def get_child_at_index(self, index):
        start = self.data_ptr.GetValueAsUnsigned()
        address = start + index * self.element_type_size
        element = self.data_ptr.CreateValueFromAddress("[%s]" % index, address, self.element_type)
        return element

    def update(self):
        self.length = self.valobj.GetChildMemberWithName("len").GetValueAsUnsigned()
        self.buf = self.valobj.GetChildMemberWithName("buf").GetChildMemberWithName("inner")

        self.data_ptr = unwrap_unique_or_non_null(self.buf.GetChildMemberWithName("ptr"))

        self.element_type = self.valobj.GetType().GetTemplateArgumentType(0)
        self.element_type_size = self.element_type.GetByteSize()

    def has_children(self):
        return True

Finally I realized the reason for my failure was because the lldb with version 17.x provided by codelldb cannot infer the element_type:

self.element_type = self.valobj.GetType().GetTemplateArgumentType(0)

I guess It's can be solved by bumping lldb version to 18.x. I can't do it by myself because I don't know how to adapt this in codelldb. Oops, codelldb hasn't been updated in a long time

Also seeing this on RustRover, seems rust-lang/rust#126793 changed lldb_providers.py , I'll see if I can submit an issue..

[joshuataylor]

codelldb doesn't need to be updated often if it's working (lldb doesn't really update), apart from major updates like these :-)

[Shelim]

Any progress on this (or workarounds)? :)

[Shelim]

Workaround: when compiling specify +nightly-2024-08-01 instead of +nightly

[vadimcn]

As of v1.11, CodeLLDB will just use formatters shipped with rustc.

[MartyMcFlyInTheSky]

In the rare case anyone has the same problem as I did:

I tried to use codelldb from neovim, extracted the .vsix package (just a normal zip package) and moved the contents of extension to ~/.local/share/codelldb. However that gets rid of the toplevel extension folder, and apparently codelldb can't find it's extension root if the toplevel directory is not named extension (maybe needs confirmation?) and in turn it can't find its formatters. Preserving the original directory structure worked. I have this now:

~/.local/share/codelldb
$ tree -L 2
.
├── [Content_Types].xml
├── extension
│   ├── adapter
│   ├── bin
│   ├── changelog.md
│   ├── extension.js
│   ├── images
│   ├── lang_support
│   ├── lldb
│   ├── package.json
│   ├── platform.ok
│   ├── readme.md
│   └── syntaxes
└── extension.vsixmanifest

Then I symlinked codelldb to the user's bin:

ln -fs ~/.local/share/codelldb/extension/adapter/codelldb ~/.local/bin/codelldb

Now the formatters work fine.

[vadimcn]

@MartyMcFlyInTheSky I don't think this is related to the original issue. IMO, it would be more appropriate to post this comment in Discussions and reference the issue thread.
FWIW, codelldb is looking for lang_support scripts relative to itself, i.e. dirname(current_exe)/../lang_support

[MartyMcFlyInTheSky]

@vadimcn Indeed, that's probably a different matter! I'm still on this issue though. When debugging rust I think I enabled the lang_support using the hint from this thread (adding sourceLanguages = {'rust'},to dap configuration in question). This turns the output from:

  Local
    : {waker:0x00007fffffffa7e8, local_waker:0x00007fffffffa7e8, ...}
    _task_context: {waker:0x00007fffffffa7e8, local_waker:0x00007fffffffa7e8, ...}
    ctx: {enumerator:0}
      domain_curr: {...}
      domain_interm: {...}
        $variants$: {...}
          $variant$: {...}
            value: {...}
              __0: {...}
                name: {...}
                remote_address: {...}
                  vec: {len:7}
                    buf: {...}
                      _marker: <not available>
                      inner: {...}
                        alloc: <not available>
                        cap: {__0:7}
                        ptr: {...}
                          _marker: <not available>
                          pointer: {pointer:"cache12"}
                    len: 7
                remote_path: {...}
                username: {...}
          $variant$0: {$discr$:7}

to

 Local
    : {waker:0x00007fffffffa798, local_waker:0x00007fffffffa798, ...}
    _task_context: {waker:0x00007fffffffa798, local_waker:0x00007fffffffa798, ...}
    ctx: {enumerator:0}
      [raw]: git_rsync::execution_plan::Context *
      domain_curr: {...}
      domain_interm: {...}
        : <error: invalid value object>
        [raw]: core::option::Option<git_rsync::domains::SSHDomain>
        value: {...}
          0: {username:"process", name:"SSHMUX:cache12", ...}
          [raw]: core::option::Option<git_rsync::domains::SSHDomain>::Some<git_rsync::domains::SSHDomain>

The REPL also states:

Loading Rust formatters from /home/user/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/etc

This is already a lot better and something seems to be working, but as you can see this change introduced the <error: invalid value object> again. Do I have to live with this or is there any other knob to turn?

dap adapter:

            -- Update this path
            local extension_path = vim.env.HOME .. '/.local/share/codelldb/extension/'
            local codelldb_path = extension_path .. 'adapter/codelldb'
            local liblldb_path = extension_path .. 'lldb/lib/liblldb'
            local this_os = vim.uv.os_uname().sysname;

            -- The path is different on Windows
            if this_os:find "Windows" then
                codelldb_path = extension_path .. "adapter\\codelldb.exe"
                liblldb_path = extension_path .. "lldb\\bin\\liblldb.dll"
            else
                -- The liblldb extension is .so for Linux and .dylib for MacOS
                liblldb_path = liblldb_path .. (this_os == "Linux" and ".so" or ".dylib")
            end

            dap.adapters.codelldb = {
                type = 'server',
                port = '${port}',
                host = '127.0.0.1',
                -- This is needed to tell codelldb to use rust formatters (https://github.com/vadimcn/codelldb/issues/1195)
                executable = {
                  command = codelldb_path,
                  args = { '--liblldb', liblldb_path, '--port', '${port}' },
                },
                enrich_config = function(cfg, on_config)
                    on_config(cfg)
                end,
            }

dap configuration (json):

        {
            "type": "codelldb",
            "request": "launch",
            "name": "debug sync",
            "sourceLanguages": ["rust"],
            "program": "./target/debug/git-rsync",
            "args": ["sync"],
        },