I'm new to Rust/Cargo and been struggling to address an issue when compiling a new Yocto recipe for gst-plugins-rs, the Cargo.toml file can be found in this directory structure.
../gstreamer1.0-plugins-rs/0.12.11-r0/git/
├── audio
│ ├── audiofx
│ ├── claxon
│ ├── csound
│ ├── lewton
│ └── spotify
├── Cargo.lock
├── Cargo.lock.orig
├── Cargo.toml
├── cargo_wrapper.py
├── CHANGELOG.md
| ...
└── video
├── cdg
...
└── webp
The Cargo.toml basically consists of the following.
[workspace]
resolver = "2"
members = [
"audio/audiofx"
"audio/claxon"
...
]
default-members = [
"audio/audiofx"
"audio/claxon"
...
]
[workspace.package]
version = "0.12.11"
repository = "https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs"
edition = "2021"
rust-version = "1.70"
[workspace.dependencies]
once_cell = "1"
glib = { git = "https://github.com/gtk-rs/gtk-rs-core", branch = "0.19", version = "0.19" }
...
gtk = { package = "gtk4", git = "https://github.com/gtk-rs/gtk4-rs", branch = "0.8", version = "0.8"}
...
gst = { package = "gstreamer", git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs", branch = "0.22", version = "0.22" }
...
Regarding the Yocto Recipe there's not much out of the ordinary, only a custom do_install that moves .so files, but it's failing in the do_compile stage. The recipe is based off this old patch request, but has been updated to more recent versions. Basically consisting of the following,
...
SRC_URI = " \
git://gitlab.freedesktop.org/gstreamer/gst-plugins-rs.git;protocol=https;branch=0.12;name=default; \
gitsm://gitlab.freedesktop.org/gstreamer/gstreamer-rs.git;protocol=https;branch=0.22;name=gstreamer-rs;destsuffix=cargo_home/git/db/gstreamer-rs-79e52a2d27eb91a3 \
git://github.com/gtk-rs/gtk-rs-core.git;protocol=https;branch=0.19;name=gtk-rs-core;destsuffix=cargo_home/git/db/gtk-rs-core-7be42ca38bd6361c \
git://github.com/gtk-rs/gtk4-rs;protocol=https;branch=0.8;name=gtk4-rs;destsuffix=cargo_home/git/db/gtk4-rs-e74ad56283dfeb5e \
git://github.com/rust-av/ffv1.git;protocol=https;branch=master;name=ffv1;destsuffix=cargo_home/git/db/ffv1-08f2e3b26709fb34 \
git://github.com/rust-av/flavors;protocol=https;branch=master;name=flavors;destsuffix=cargo_home/git/db/flavors-0f978a4d88ad8592 \
crate://crates.io/adler/1.0.2 \
crate://crates.io/adler32/1.2.0 \
crate://crates.io/aes/0.8.4 \
crate://crates.io/aho-corasick/1.1.3 \
...
inherit cargo pkgconfig
DEPENDS = " \
gstreamer1.0 \
gstreamer1.0-plugins-good \
"
...
The error I'm receiving is the following,
cargo build -v --frozen --target aarch64-lmp-linux-gnu --release --manifest-path=.../gstreamer1.0-plugins-rs/0.12.11-r0/git//Cargo.toml
NOTE: cargo build -v --frozen --target aarch64-lmp-linux-gnu --release --manifest-path=.../gstreamer1.0-plugins-rs/0.12.11-r0/git//Cargo.toml
error: failed to load source for dependency `gtk4-rs`
Caused by:
Unable to update .../gstreamer1.0-plugins-rs/0.12.11-r0/cargo_home/git/db/gtk4-rs-e74ad56283dfeb5e
Caused by:
found a virtual manifest at `.../gstreamer1.0-plugins-rs/0.12.11-r0/cargo_home/git/db/gtk4-rs-e74ad56283dfeb5e/Cargo.toml` instead of a package manifest
Perhaps I need to convert gtk4-rs's Cargo.toml to a package manifest? Or is there a cargo command that needs to be changed so that it expects a virtual manifest?
Any suggestions would be much appreciated and I'm happy to share more details. Also if there are some cargo debugging commands I could run, please let me know.
I initially thought the SRC_URI, specifically the destsuffix, was the issue initially, but when removing the sources, e.g. gstreamer-rs, gtk-rs-core, etc, I've confirmed that gst-plugins-rs is looking for those other sources at those paths.
I’m not familiar with Yocto, so I can’t advise you on exactly how to fix this problem, but I am familiar with Cargo. Based on the build error, you seem to be trying to replace git dependencies with path dependencies.
Cargo has a special behavior for Git dependencies, that no other dependency type has: it will search the contents of (the requested revision of) the repository for the requested package (here gtk4). So, when Cargo looks at https://github.com/gtk-rs/gtk4-rs, it searches until it finds the package manifest https://github.com/gtk-rs/gtk4-rs/blob/main/gtk4/Cargo.toml, not the workspace manifest https://github.com/gtk-rs/gtk4-rs/blob/main/Cargo.toml. (I believe the workspace manifest does not at all affect the search, but I could be wrong.)
path dependencies have no such search behavior — the path must be to the
directory containing exactly the needed package manifest. So, when you wish to transform a git dependency to a path dependency, you must find the correct package directory within the repository and use that path in the dependency.
The reason Cargo says “found a virtual manifest” is that a virtual manifest is a manifest that does not define a package, only a workspace. For your purposes, understand the error as “no package found in this directory, but FYI, we did find something else that is not a package”. You need to point Cargo to the correct (sub)directory instead.