error: parsing package.metadata.cargo-xbuild section failed

[parasyte]

I get this new error message (introduced in #57) with no additional way to diagnose the cause.

error: parsing package.metadata.cargo-xbuild section failed
note: run with `RUST_BACKTRACE=1` for a backtrace

Setting RUST_BACKTRACE=1 hides the second line from the error message and produces no backtrace.

This causes my CI to fail. E.g. https://travis-ci.org/rust-console/cargo-n64/builds/650914215

FWIW, the cargo-n64 repo is setup with a workspace manifest, and I do not have a package.metadata.cargo-xbuild section in any of the crate manifests. cargo xbuild is invoked something like this:

cargo xbuild --target=/tmp/mips-nintendo64-none.json --package=hello-ipl3font --release

Where the contents of the target JSON file is:

{
  "arch": "mips",
  "cpu": "mips3",
  "data-layout": "E-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32:64-S64",
  "disable-redzone": true,
  "env": "unknown",
  "executables": true,
  "features": "+mips3,+gp64,+fpxx,+nooddspreg",
  "linker": "rust-lld",
  "linker-flavor": "ld.lld",
  "llvm-target": "mips-unknown-unknown",
  "os": "none",
  "panic-strategy": "abort",
  "pre-link-args": {
    "ld.lld": [
      "--script=/tmp/linker.ld"
    ]
  },
  "relocation-model": "static",
  "target-c-int-width": "32",
  "target-endian": "big",
  "target-pointer-width": "32",
  "vendor": "nintendo64"
}

And the contents of the linker script:

ENTRY(_start)

SECTIONS {
    . = 0x80000400;
    __boot_start = .;

    .boot : {
        *(.boot)
    }

    .text : {
        *(.text .text.*)
    }

    .rodata : {
        *(.rodata .rodata.*)
    }

    .data : {
        *(.data .data.*)
    }

    .bss : {
        . = ALIGN(4);
        __bss_start = .;
        *(.bss .bss.*)
        __bss_end = .;
    }

    . = ALIGN(2);
    __rom_end = . - __boot_start + 0xB0001000;

    /DISCARD/ : {
        *(.MIPS.*)
        *(.comment)
        *(.mdebug.*)
        *(.pdr)
        *(.reginfo)

        /*
         * We may need the global offset table some day.
         * Our target is currently set with a static relocation-model, so this
         * might not be needed after all.
         */
        *(.got)
    }
}

[parasyte]

I've inserted some print statements to help debug, and it is failing here:

cargo-xbuild/src/config.rs

Line 27 in 8508ef8

.ok_or("Cannot infer the root project id")?;

cc @ascjones

[phil-opp]

Thanks for reporting this! I can reproduce this error with your repository and I'm trying to fix it.

[phil-opp]

I think I found the error. The problem is that your project is using a virtual manifest at the workspace root, which we forgot to handle in the code introduced in #57. I opened #61 to fix this. Unfortunately, we can't load any config for such projects since it's not clear which Cargo.toml should be used for loading the config. For this reason we print a warning and use the default config.

Could you try the code in #61 and test whether this approach works for you? You can install the version through:

cargo install cargo-xbuild --git https://github.com/rust-osdev/cargo-xbuild.git --branch fix-60 --debug --force

[parasyte]

Thanks for the quick turnaround on this. I'll give it a shot and report back.

Side note: I'm also considering pulling cargo-xbuild as a library dependency, instead of calling the binary through the system interface. That will take care of the virtual manifest problem, since the correct manifest can be passed directly.

[phil-opp]

@parasyte Did you try whether it works for you now?

[parasyte]

It works! We also got it integrated as a library. 👍

[phil-opp]

Perfect, thanks for the update!