Cargo.toml files using absolute paths are not correctly parsed

[gbbosak]

On Fuchsia; we use a gen-cargo script to generate Cargo.toml files from our custom build system that are compatible with RLS. These files use absolute paths to their dependencies, and this seems to break rust-analyzer, but functions just fine with RLS.

Steps to repro:

• Download Fuchsia (see here): https://fuchsia.dev/fuchsia-src/development/source_code
• fx set core.x64 --release
• fx build (this may take several hours, and requires a pretty powerful machine)
• fx gen-cargo //src/connectivity/bluetooth/profiles/bt-a2dp-sink:bin
• Open fuchsia/src/connectivity/bluetooth/profiles/bt-a2dp-sink in an editor that supports rust-analyzer (such as VSCode)
• Observe errors such as this "Unable to open 'channel.rs': Unable to read file (Error: File not found (/mntpnt/fuchsia/src/connectivity/bluetooth/profiles/bt-a2dp-sink/mntpnt/fuchsia/garnet/public/rust/fuchsia-zircon/src/channel.rs))."
  when trying to navigate between files with rust-analyzer.

[edwin0cheng]

I did try to replicate your case with a full path deps and but it did works :

# /sandbox/temp/foo/crates/foo.toml

[package]
name = "foo"
version = "0.1.0"
edition = "2018"

[dependencies]
baz = {path="/sandbox/temp/foo/crates/baz"}

Would you mind to just share the post-generated Cargo.toml ?

[matklad]

Haven't looked into this yet, but an interesting thing for Fuchsia use-case is that we don't require a Cargo.toml. Instead a rust-project.json file can be used, which just specifies the crates directly (ie, it's a lower-level in comparison to .toml). We don't really have any good docs for this functionality (mainly because there are no users I know of), but this tests shows an example:

https://github.com/rust-analyzer/rust-analyzer/blob/8b278b1ab660df0728508e45e88ac769a2e03a58/crates/ra_lsp_server/tests/heavy_tests/main.rs#L281-L354

In theory, producing something like project-json from a custom build system should be easier than faking whole Cargo.tomls

[gbbosak]

# Copyright 2019 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

[package]
name = "bt_a2dp_sink"
version = "0.1.0"
edition = "2018"
license-file = "LICENSE"
authors = ["rust-fuchsia@fuchsia.com"]
description = "Rust crate for Fuchsia OS"
repository = "https://fuchsia.googlesource.com"

[[bin]]

name = "bt_a2dp_sink"
path = "/mntpnt/fuchsia/src/connectivity/bluetooth/profiles/bt-a2dp-sink/src/main.rs"

[features]
default = []



[dev-dependencies]

[dependencies]
serde_json = "1"
slab = "0.4"
parking_lot = "0.9"
lazy_static = "1"
serde_derive = "1.0.99"
matches = "0.1.8"
failure = "0.1.1"
bitfield = "0.13"

[dependencies.bt_a2dp]
path = "/mntpnt/fuchsia/out/default/gen/src/connectivity/bluetooth/lib/bt-a2dp/bt-a2dp"
version = "0.1.0"

[dependencies.bt_avdtp]
path = "/mntpnt/fuchsia/out/default/gen/src/connectivity/bluetooth/lib/bt-avdtp/bt-avdtp"
version = "0.1.0"

[dependencies.fuchsia_async]
path = "/mntpnt/fuchsia/out/default/gen/garnet/public/rust/fuchsia-async/fuchsia-async"
version = "0.1.0"

[dependencies.fidl_fuchsia_media_playback]
path = "/mntpnt/fuchsia/out/default/gen/sdk/fidl/fuchsia.media.playback/fuchsia.media.playback-rustc"
version = "0.1.0"

[dependencies.fidl_fuchsia_cobalt]
path = "/mntpnt/fuchsia/out/default/gen/zircon/system/fidl/fuchsia-cobalt/fuchsia-cobalt-rustc"
version = "0.1.0"

[dependencies.fuchsia_bluetooth]
path = "/mntpnt/fuchsia/out/default/gen/src/connectivity/bluetooth/lib/fuchsia-bluetooth/fuchsia-bluetooth"
version = "0.1.0"

[dependencies.fuchsia-zircon]
path = "/mntpnt/fuchsia/out/default/gen/garnet/public/rust/fuchsia-zircon/fuchsia-zircon"
version = "0.3.3"

[dependencies.log]
version = "0.4.4"
features = ["std"]

[dependencies.fuchsia-inspect]
path = "/mntpnt/fuchsia/out/default/gen/src/lib/inspect/rust/fuchsia-inspect/fuchsia-inspect"
version = "0.1.0"

[dependencies.fidl]
path = "/mntpnt/fuchsia/out/default/gen/garnet/public/lib/fidl/rust/fidl/fidl"
version = "0.1.0"

[dependencies.fuchsia_cobalt]
path = "/mntpnt/fuchsia/out/default/gen/src/lib/cobalt/rust/fuchsia-cobalt"
version = "0.1.0"

[dependencies.fidl_fuchsia_media]
path = "/mntpnt/fuchsia/out/default/gen/sdk/fidl/fuchsia.media/fuchsia.media-rustc"
version = "0.1.0"

[dependencies.fuchsia_syslog]
path = "/mntpnt/fuchsia/out/default/gen/garnet/public/rust/fuchsia-syslog/fuchsia-syslog"
version = "0.1.0"

[dependencies.fuchsia_inspect_contrib]
path = "/mntpnt/fuchsia/out/default/gen/src/lib/inspect/rust/fuchsia-inspect-contrib/fuchsia-inspect-contrib"
version = "0.1.0"

[dependencies.fidl_fuchsia_bluetooth_bredr]
path = "/mntpnt/fuchsia/out/default/gen/sdk/fidl/fuchsia.bluetooth.bredr/fuchsia.bluetooth.bredr-rustc"
version = "0.1.0"

[dependencies.fidl_fuchsia_bluetooth]
path = "/mntpnt/fuchsia/out/default/gen/sdk/fidl/fuchsia.bluetooth/fuchsia.bluetooth-rustc"
version = "0.1.0"

[dependencies.fdio]
path = "/mntpnt/fuchsia/out/default/gen/garnet/public/rust/fdio/fdio"
version = "0.2.0"

[dependencies.futures]
version = "0.3.1"
features = ["io-compat"]

[dependencies.fidl_fuchsia_mem]
path = "/mntpnt/fuchsia/out/default/gen/zircon/system/fidl/fuchsia-mem/fuchsia-mem-rustc"
version = "0.1.0"

[dependencies.fuchsia-component]
path = "/mntpnt/fuchsia/out/default/gen/garnet/public/rust/fuchsia-component/fuchsia-component"
version = "0.1.0"

[dependencies.bt_a2dp_sink_metrics]
path = "/mntpnt/fuchsia/out/default/gen/src/connectivity/bluetooth/profiles/bt-a2dp-sink/bt_a2dp_sink_metrics_rustlib"
version = "1.0.0"

[dependencies.fidl_fuchsia_bluetooth_avdtp]
path = "/mntpnt/fuchsia/out/default/gen/sdk/fidl/fuchsia.bluetooth.avdtp/fuchsia.bluetooth.avdtp-rustc"
version = "0.1.0"

[patch]

[patch.crates-io]

[patch.crates-io.fuchsia-cprng]
path = "/mntpnt/fuchsia/third_party/rust_crates/../../garnet/public/rust/fuchsia-cprng"

[patch.crates-io.cmake]
path = "/mntpnt/fuchsia/third_party/rust_crates/tiny_mirrors/cmake"

[patch.crates-io.rust-crypto]
path = "/mntpnt/fuchsia/third_party/rust_crates/../rust-mirrors/rust-crypto"

[patch.crates-io.servo-freetype-sys]
path = "/mntpnt/fuchsia/third_party/rust_crates/tiny_mirrors/servo-freetype-sys"

[patch.crates-io.xi-rope]
path = "/mntpnt/fuchsia/third_party/rust_crates/../rust-mirrors/xi-editor/rust/rope"

[patch.crates-io.xi-core-lib]
path = "/mntpnt/fuchsia/third_party/rust_crates/../rust-mirrors/xi-editor/rust/core-lib"

[patch.crates-io.xi-rpc]
path = "/mntpnt/fuchsia/third_party/rust_crates/../rust-mirrors/xi-editor/rust/rpc"

[patch.crates-io.backtrace-sys]
path = "/mntpnt/fuchsia/third_party/rust_crates/tiny_mirrors/backtrace-sys"

[patch.crates-io.xi-trace]
path = "/mntpnt/fuchsia/third_party/rust_crates/..//rust-mirrors/xi-editor/rust/trace"

[patch.crates-io.xi-trace-dump]
path = "/mntpnt/fuchsia/third_party/rust_crates/../rust-mirrors/xi-editor/rust/trace-dump"

[patch.crates-io.winapi-util]
path = "/mntpnt/fuchsia/third_party/rust_crates/tiny_mirrors/winapi-util"

[patch.crates-io.web-sys]
path = "/mntpnt/fuchsia/third_party/rust_crates/tiny_mirrors/web-sys"

[patch.crates-io.winapi]
path = "/mntpnt/fuchsia/third_party/rust_crates/tiny_mirrors/winapi"

[patch.crates-io.xi-unicode]
path = "/mntpnt/fuchsia/third_party/rust_crates/../rust-mirrors/xi-editor/rust/unicode"

[patch.crates-io.pkg-config]
path = "/mntpnt/fuchsia/third_party/rust_crates/tiny_mirrors/pkg-config"

[profile]

[profile.release]
lto = "thin"
panic = "abort"
opt-level = "z"

[edwin0cheng]

@gbbosak The following are just my guesses:

Did any Cargo.toml generated in /mntpnt/fuchsia/src ? If I understand correctly, RA use cargo-metadata and It will search through ancestor directory to get relevant workspace information.

Maybe that Cargo.toml in mntpnt/fuhsia/src confuses the actual path data ?

BTW, I would recommend to discuses in RA Zulip Channel.

[gbbosak]

We're looking into whether or not emitting a rust-project.json file would be feasible. I'll update this when I find out the results of that.

[gbbosak]

We've switched to rust-project.json and it works now. Closing this bug.