Can't step into libstd with gdb on Windows

[elahn]

fn main() {
    let mut input = String::new();

When I try to step in, I get:
Source C:\bot\slave\nightly-dist-rustc-win-gnu-64\build\obj\../src/libcollections/string.rs is not available.

When I set a breakpoint in string.rs and start a debug session, I get the error:
No source file named d:\dev\gnu\rust\src\libcollections\string.rs.
Note: this does not mean the file doesn't exist on the filesystem, it means it's not in the debug binary.

Workaround:

Set RUST_SRC_PATH=C:\bot\slave\nightly-dist-rustc-win-gnu-64\build\src

Either:

• Copy/move rust source code to C:\bot\slave\nightly-dist-rustc-win-gnu-64\build\src
• Or, as administrator:

C:\bot\slave\nightly-dist-rustc-win-gnu-64>mklink build C:\Users\Elahn\.multirust\toolchains\nightly-x86_64-pc-windows-gnu\lib\rustlib
symbolic link created for build <<===>> C:\Users\Elahn\.multirust\toolchains\nightly-x86_64-pc-windows-gnu\lib\rustlib

[elahn]

I've edited the issue: my local build wasn't being used because cargo.exe didn't exist in [build-dir]\bin

So, the issue is: debug info (source filename/location) is being generated when rust is built, but isn't being updated when linking libstd into the target binary.

[michaelwoerister]

Interesting. Thanks for the report!

[retep998]

If you use VS Code as your debugger you can use https://blogs.msdn.microsoft.com/vcblog/2016/12/12/december-update-for-the-visual-studio-code-cc-extension/#map to remap the paths.

[tmillr]

I'm running into this after installing stable rustc and cargo from nixpkgs. The rust std libs end up having a path which leads to a non-existent temp dir (i.e. the build dir).

I don't think $RUST_SRC_PATH works for this anymore: when I build a project using the aforementioned compilers, I still end up with the same paths (leading to the temp dir) embedded in my final bin/artifact.

I know this can be remapped in the debugger, but I don't feel that that's ideal. The name of the build dir changes with each build and lldb doesn't accept a pattern for remapping src paths. rustc now also has a similar option/flag, but it doesn't accept a pattern either AFAIK.

Perhaps there is a tool that can edit symbol src paths within an object file? Is there a way to set the src paths when the std libs themselves are built?

[spacewulf]

I'm running into this after installing stable rustc and cargo from nixpkgs. The rust std libs end up having a path which leads to a non-existent temp dir (i.e. the build dir).

I don't think $RUST_SRC_PATH works for this anymore: when I build a project using the aforementioned compilers, I still end up with the same paths (leading to the temp dir) embedded in my final bin/artifact.

This is what I'm running in to as well, for whatever reason previously working projects (ironically no_std ones) are complaining about building the standard library and it looks towards the build directory instead of the currently used env.RUST_SRC_PATHvalue in my devShell.

If you figured out a way of getting around it, I'm all ears as this has been driving me nuts trying to debug.