Do you need a Long-Term-Support version of Rust? It's not going to happen. BUT here's an alternative: get rid of incompatible dependencies. This tool creates a local fork of crates.io registry and lets you yank any crates from it.
It clones the crates.io registry to a local directory, and enables Cargo's source replacement feature in .cargo/config. Cargo still thinks it uses the crates.io registry, but fetches it from the local directory. Cargo.lock remains compatible with the crates.io registry!
The local fork can be modified at will. Currently yanking and unyanking of arbitrary crates is supported.
sh
cargo install -f lts --vers=0.3.0-alpha.1
git command in PATH.Tested on macOS and Linux.
cd to your project's directory (where the Cargo.toml is), and run:
sh
cargo lts yank "SPEC"
where the SPEC is crate's name followed by semver range, without a space in between. Semver range starts with >=, <= or = followed by a version. It must be quoted (because < and > are shell special characters). For example, to yank serde version 1.0.118 and all newer versions of serde, run:
sh
cargo lts yank "serde>=1.0.118"
On the first run it will set up the registry fork, which may take a minute. After yanking or unyanking run cargo update to apply the changes to your Cargo.lock.
Multiple crates can be yanked at the same time:
sh
cargo lts yank "backtrace<=0.1.8" "gcc<=0.3.0" "lazy_static<=0.1.0" "libc^0.1.0" "mio<=0.3.7" "mio=0.6.0" "nix=0.5.0" "num<=0.1.25" "pkg-config<=0.3.2" "rand<=0.3.8" "rustc-serialize<=0.3.21" "semver<=0.1.5" "void<=0.0.4" "winapi<=0.1.17"
sh
cargo lts update
Note that cargo update alone won't fetch new creates from the crates.io registry, because it's set up to use a local fork. You need to update the local fork with cargo lts update.
This will delete the fork and set config back to normal:
sh
cargo lts reset
or you can edit .cargo/config yourself and remove the replace-with line.