Indexmap Dep Not properly Compiled

[gluax]

Hey when trying to compile with Bazel I get the following error for the Indexmap version-1.3.0 dependency.

The following is the BUILD file generated for said dep.

cargo-raze crate build file.

DO NOT EDIT! Replaced on runs of cargo-raze
"""
package(default_visibility = [
  # Public for visibility by "@raze__crate__version//" targets.
  #
  # Prefer access through "//cargo", which limits external
  # visibility to explicit Cargo.toml dependencies.
  "//visibility:public",
])

licenses([
  "notice", # "Apache-2.0,MIT"
])

load(
    "@io_bazel_rules_rust//rust:rust.bzl",
    "rust_library",
    "rust_binary",
    "rust_test",
)


# Unsupported target "bench" with type "bench" omitted
# Unsupported target "build-script-build" with type "custom-build" omitted
# Unsupported target "equivalent_trait" with type "test" omitted
# Unsupported target "faststring" with type "bench" omitted

rust_library(
    name = "indexmap",
    crate_root = "src/lib.rs",
    crate_type = "lib",
    edition = "2015",
    srcs = glob(["**/*.rs"]),
    deps = [
        "//cargo/vendor/serde-1.0.101:serde",
    ],
    rustc_flags = [
        "--cap-lints=allow",
    ],
    version = "1.3.0",
    crate_features = [
        "serde",
        "serde-1",
    ],
)

# Unsupported target "macros_full_path" with type "test" omitted
# Unsupported target "quick" with type "test" omitted
# Unsupported target "serde" with type "test" omitted
# Unsupported target "tests" with type "test" omitted

My rust version is 1.38 and alloc should compile and if not the package build.rs should add the std lib.
Is there a way I can help fix this or anything?

[acmcarther]

Here's the relevant snippet of indexmap-1.30.0
https://github.com/bluss/indexmap/blob/c8204515dc1f5bc74c89ca440ecbaa470f30520d/src/lib.rs#L55-L57

#[cfg(not(has_std))]
#[macro_use(vec)]
extern crate alloc;

It looks like has_std is populated by build.rs via the autocfg crate
https://github.com/bluss/indexmap/blob/c8204515dc1f5bc74c89ca440ecbaa470f30520d/build.rs#L4-L6

    let ac = autocfg::new();
    ac.emit_sysroot_crate("std");
    autocfg::rerun_path(file!());

From the documentation of autocfg::emit_sysroot_crate, the function "Emits a config value has_CRATE if probe_sysroot_crate returns true."
https://github.com/cuviper/autocfg/blob/15ea2ca3b6bcdc2af7dab514b571e55fd9370957/src/lib.rs#L265-L270

    /// Emits a config value `has_CRATE` if `probe_sysroot_crate` returns true.
    pub fn emit_sysroot_crate(&self, name: &str) {
        if self.probe_sysroot_crate(name) {
            emit(&format!("has_{}", mangle(name)));
        }
    }

(Nitty gritty aside: It seem the way this works is the autocfg library tries to run rustc over a file containing the single "extern $some_crate", and identifies whether or not that compiles)

TL;DR: indexmap depends on --cfg has_std, which is populated by the build.rs when the std crate is available.*

I don't think this build.rs file can work in the context of Bazel. Your best bet is probably to include the config value manually in an "additional_flags" [raze] parameter. An example:

cargo-raze/examples/remote/complicated_cargo_library/cargo/Cargo.toml

Lines 19 to 22 in 3b9cb84

	[raze.crates.proc-macro2.'0.4.28']
	additional_flags = [
	"--cfg=use_proc_macro",
	]

[gluax]

Ahh great that helped a bunch thanks for clearing that up!

Just one more quick question if you could help with that it would be great.
If I am using something lisqlite3_sys with bazel and cargo raze would I need to do something similar to what you all did for openssl?

[acmcarther]

Yeah, I think you'd need to do something similar.

I actually did this work once before for bringing in libsqlite3-sys for rusqlite, and it looks like I decided to totally overwrite the libsqlite3-sys dependency. I can't remember why... Here's the settings for rusqlite:
https://github.com/acmcarther/void/blob/590be5e8df498dc791e10ba0f35083e5493adcd0/third_party/cargo/Cargo.toml#L43-L49

[raze.crates.rusqlite.'0.14.0']
skipped_deps = [
  "libsqlite3-sys-0.9.3"
]
additional_deps = [
  "@//third_party/cargo/overrides/libsqlite3-sys:libsqlite3_sys"
]

And the libsqlite override library:
https://github.com/acmcarther/void/tree/master/third_party/cargo/overrides/libsqlite3-sys

I think the significant changes were:

• Update the cargo-raze generated BUILD file to use my workspace's bindgen brought in by cargo-raze
• Update the cargo-raze generated BUILD file to depend on my workspace's sqlite3 package. It looks like I hand wrote that BUILD file... I'm not sure if that's still the "easiest" way to do this.

https://github.com/acmcarther/void/tree/master/third_party/sqlite3

I feel like these Cargo crate transformations should be captured somewhere so we can pool our efforts. I'll think about the best way to accomplish this. Ideas very welcome of course!

[gluax]

Hey thanks for all the help and sorry for late reply. That was super helpful.

We can capture these transformation in a separate repo that just has a folder for the different cargo packages(when needed). Then just link that to the main page here, as one idea. Although I suppose that could be a nightmare with the different cargo package versions.