./x.py build --verbose and config.toml build.verbose=2 don't trigger cargo --verbose

[devurandom]

Passing --verbose to ./x.py build and setting build.verbose in config.toml does not cause --verbose to be passed to cargo, which results in a non-verbose build.

I am trying to build rust-1.17.0 as follows:

   cat <<- EOF > "${S}"/config.toml
        [llvm]
        optimize = $(toml_usex !debug)
        release-debuginfo = $(toml_usex debug)
        assertions = $(toml_usex debug)
        [build]
        build = "${CTARGET}"
        host = "${CTARGET}"
        target = "${CTARGET}"
        cargo = "${WORKDIR}/${cargo_stage0}/cargo/bin/cargo"
        rustc = "${WORKDIR}/${rustc_stage0}/rustc/bin/rustc"
        docs = $(toml_usex doc)
        submodules = false
        python = "${EPYTHON}"
        locked-deps = true
        vendor = true
        verbose = 2
        [install]
        prefix = "${EPREFIX}/usr"
        libdir = "$(get_libdir)/${P}"
        docdir = "share/doc/${P}"
        mandir = "share/${P}/man"
        [rust]
        optimize = $(toml_usex !debug)
        debuginfo = $(toml_usex debug)
        debug-assertions = $(toml_usex debug)
        use-jemalloc = $(toml_usex jemalloc)
        default-linker = "${linker}"
        default-ar = "${archiver}"
        rpath = false
        [target.x86_64-unknown-linux-gnu]
        cc = "${c_compiler}"
        cxx = "${cxx_compiler}"
        llvm-config = "${llvm_config}"
    EOF

   ./x.py build --verbose --config="${S}"/config.toml

[alexcrichton]

@devurandom just to confirm, this is the build for rustbuild itself? I know that location doesn't handle --verbose for Cargo, but all others should.

[devurandom]

@alexcrichton I was trying to build rustc.

You can find the complete, but WIP ebuild in my Gentoo overlay. It is based on the Gentoo ebuild for 1.16.0, but tries to adapt to the changes in the build-system from 1.16 to 1.17 and switch from Makefiles to x.py.

[alexcrichton]

@devurandom do you have logs or a gist of the wrong behavior, maybe with comments as to what the expected correct behavior is?

[devurandom]

E.g. when I run cargo build --verbose, I see the rustc commandline for every package being build. I would like to see the same when building Rust using ./x.py, but I can't convince the build-system to show it to me (s.a.).

This makes it very hard for me to debug another issue, where the bootstrapping rustc complains that it can't find crate for std (error[E0463]). I was hoping that seeing the actual invocation of rustc would give me a fresh idea what's going on there.

[alexcrichton]

Do you have logs of what's going on? The logs in the linked thread there look like --verbose is working?

[devurandom]

Build log when using the current ebuild: https://gist.github.com/devurandom/1223ee18f46c6ed866b386ec7009dbbb

You are right that, after bootstrapping, the build was verbose in the logs linked from the forums post. But even there you will notice that the bootstrap process is not verbose (see lines 108 to 118 of the Gist). It just so happens that at the time I posted that Gist I tricked the bootstrap process into succeeding, which is why most of what you see is output of later stages of the build.

The major difference between the ebuild posted in the Gist and the current version of the ebuild is that the former uses the system Rust compiler to bootstrap (which is why it works during bootstrapping, but fails later), while the latter uses the Rust compiler it downloads from https://static.rust-lang.org/dist/rustc-1.16.0-x86_64-unknown-linux-gnu.tar.gz (which shows the libstd issue already during bootstrapping).

[alexcrichton]

Ok thanks for the clarification! In that case I believe the fix would just go somewhere around here

[devurandom]

Thanks for the hint. I came across that part about a hundred times, but failed to make the connection. Please find the fix in #42186.

On the other topic: Is it possible to make Cargo / rustc output a list of directories where it searched for a "crate"? I tried setting LD_LIBRARY_PATH and RUSTC_SYSROOT, but I cannot make rustc pickup the libstd-13f36e2630c2d79b.so in rustc-1.16.0-x86_64-unknown-linux-gnu/rustc/lib, so I would like to know what exactly (i.e. actual library name) it is searching where (which sysroot and library path does it see).