Yggdrasil and jlrs

In the previous chapter we saw how we could write a recipe to build a Rust crate and contribute it to Yggdrasil to distribute it as a JLL package. When the crate we want to build depends on jlrs, we have to deal with a complication: we need to build the library against every version of Julia that we want to support. This requires a few adjustments to the recipe.

The recipe should look as follows:

# Note that this script can accept some limited command-line arguments, run
# `julia build_tarballs.jl --help` to see a usage message.
using BinaryBuilder, Pkg

# See https://github.com/JuliaLang/Pkg.jl/issues/2942
# Once this Pkg issue is resolved, this must be removed
uuid = Base.UUID("a83860b7-747b-57cf-bf1f-3e79990d037f")
delete!(Pkg.Types.get_last_stdlibs(v"1.6.3"), uuid)

name = "{{crate_name}}"
version = v"0.1.0"
julia_versions = [v"1.10", v"1.11", v"1.12"]

# Collection of sources required to complete build
sources = [
    GitSource("https://github.com/{{user}}/{{crate_name}}.git",
              "{full commit hash, e.g.: 52ab80563a07d02e3d142f85101853bbf5c0a8a1}"),
]

# Bash recipe for building across all platforms
script = raw"""
cd $WORKSPACE/srcdir/{{crate_name}}
cargo build --release --verbose
install_license LICENSE
install -Dvm 0755 "target/${rust_target}/release/"*{{crate_name}}".${dlext}" "${libdir}/lib{{crate_name}}.${dlext}"
"""

include("../../L/libjulia/common.jl")
platforms = vcat(libjulia_platforms.(julia_versions)...)

# Rust toolchain for i686 Windows is unusable
is_excluded(p) = Sys.iswindows(p) && nbits(p) == 32
filter!(!is_excluded, platforms)

# The products that we will ensure are always built
products = [
    LibraryProduct("lib{{crate_name}}", :librustfft),
]

# Dependencies that must be installed before this package can be built
dependencies = [
    BuildDependency("libjulia_jll"),
    Dependency("Libiconv_jll"; platforms=filter(Sys.isapple, platforms)),
]

# Build the tarballs.
build_tarballs(ARGS, name, version, sources, script, platforms, products, dependencies;
               preferred_gcc_version=v"10", julia_compat="1.10", compilers=[:c, :rust])

The main differences with the recipe for a crate that doesn't depend on jlrs are:

• The workaround for issue #2942.
• The supported versions of Julia are set.
• Supported platforms are acquired via libjulia_platforms, not supported_platforms.
• libjulia_jll is added to the dependencies as a build dependency.