How to configure the gradle plugin if the rust project files are siblings?

[mainrs]

This is my project layout:

$ tree -L 1
.
├── Cargo.lock
├── Cargo.toml
├── desktop
│   ├── build.gradle.kts
│   ├── composeApp
│   ├── gradle
│   ├── gradle.properties
│   ├── gradlew
│   ├── gradlew.bat
│   ├── local.properties
│   ├── README.md
│   ├── settings.gradle.kts
│   └── uniffi-kotlin-multiplatform-bindings
├── target
├── ugl-core

The crate that uses the uniffi proc macros is ugl-core. I added the uniffi gradle plugin as a git submodule. These are the gradle files:

// settings.gradle.kts
rootProject.name = "UnifiedGameLauncher"
enableFeaturePreview("TYPESAFE_PROJECT_ACCESSORS")

pluginManagement {
    includeBuild("uniffi-kotlin-multiplatform-bindings/build-logic")
    repositories {
        google {
            mavenContent {
                includeGroupAndSubgroups("androidx")
                includeGroupAndSubgroups("com.android")
                includeGroupAndSubgroups("com.google")
            }
        }
        mavenCentral()
        gradlePluginPortal()
    }
}

dependencyResolutionManagement {
    repositories {
        google {
            mavenContent {
                includeGroupAndSubgroups("androidx")
                includeGroupAndSubgroups("com.android")
                includeGroupAndSubgroups("com.google")
            }
        }
        mavenCentral()
    }
}

plugins {
    id("org.gradle.toolchains.foojay-resolver-convention") version "1.0.0"
}

include(":composeApp")

// build.gradle.kts
plugins {
    // this is necessary to avoid the plugins to be loaded multiple times
    // in each subproject's classloader
    alias(libs.plugins.composeMultiplatform) apply false
    alias(libs.plugins.composeCompiler) apply false
    alias(libs.plugins.kotlinMultiplatform) apply false
}

// composeApp/settings.gradle.kts
import org.jetbrains.compose.desktop.application.dsl.TargetFormat

plugins {
    alias(libs.plugins.kotlinMultiplatform)
    alias(libs.plugins.composeMultiplatform)
    alias(libs.plugins.composeCompiler)
    alias(libs.plugins.composeHotReload)

    // Required for FFI bindings.
    id("org.jetbrains.kotlin.plugin.atomicfu") version "2.1.21"
    id("io.gitlab.trixnity.cargo.kotlin.multiplatform") version "0.6.0"
    id("io.gitlab.trixnity.uniffi.kotlin.multiplatform") version "0.6.0"
}

// Configures the linking process between Rust and Kotlin.
cargo {
    // The Cargo package is located in a `rust` subdirectory.
    packageDirectory = layout.projectDirectory.dir("..")
}

uniffi {
    formatCode = true
    generateFromLibrary {
        namespace = "ugl-core"
    }
}

kotlin {
    jvm("desktop")
    
    sourceSets {
        val desktopMain by getting
        
        commonMain.dependencies {
            implementation(compose.runtime)
            implementation(compose.foundation)
            implementation(compose.material3)
            implementation(compose.ui)
            implementation(compose.components.resources)
            implementation(compose.components.uiToolingPreview)
            implementation(libs.androidx.lifecycle.viewmodel)
            implementation(libs.androidx.lifecycle.runtimeCompose)
        }
        commonTest.dependencies {
            implementation(libs.kotlin.test)
        }
        desktopMain.dependencies {
            implementation(compose.desktop.currentOs)
            implementation(libs.kotlinx.coroutinesSwing)
        }
    }
}


compose.desktop {
    application {
        mainClass = "io.MainKt"

        nativeDistributions {
            targetFormats(TargetFormat.Dmg, TargetFormat.Msi, TargetFormat.Deb)
            packageName = "io"
            packageVersion = "1.0.0"
        }
    }
}

I get this error:

* Exception is:
org.gradle.api.ProjectConfigurationException: A problem occurred configuring project ':composeApp'.
[...]
Caused by: java.util.NoSuchElementException: Collection contains no element matching the predicate.
	at io.gitlab.trixnity.gradle.cargo.CargoPackage.<init>(CargoPackage.kt:162)
	at io.gitlab.trixnity.gradle.cargo.dsl.CargoExtension.cargoPackage$lambda$1(CargoExtension.kt:47)
	at io.gitlab.trixnity.gradle.cargo.dsl.CargoExtension.cargoPackage$lambda$2(CargoExtension.kt:46)
	at org.gradle.api.internal.provider.BiProvider.calculateOwnValue(BiProvider.java:79)
	at org.gradle.api.internal.provider.AbstractMinimalProvider.calculateValue(AbstractMinimalProvider.java:115)
	at org.gradle.api.internal.provider.TransformBackedProvider.calculateOwnValue(TransformBackedProvider.java:81)
	at org.gradle.api.internal.provider.AbstractMinimalProvider.calculateValue(AbstractMinimalProvider.java:115)
	at org.gradle.api.internal.provider.AbstractMinimalProvider.withFinalValue(AbstractMinimalProvider.java:168)
	at org.gradle.api.internal.provider.DefaultProperty.finalValue(DefaultProperty.java:162)
	at org.gradle.api.internal.provider.DefaultProperty.finalValue(DefaultProperty.java:33)
	at org.gradle.api.internal.provider.AbstractProperty.finalizeNow(AbstractProperty.java:281)
	at org.gradle.api.internal.provider.AbstractProperty.lambda$beforeRead$0(AbstractProperty.java:276)
	at org.gradle.api.internal.provider.ValueState.finalizeOnReadIfNeeded(ValueState.java:139)
	at org.gradle.api.internal.provider.AbstractProperty.beforeRead(AbstractProperty.java:276)
	at org.gradle.api.internal.provider.AbstractProperty.beforeRead(AbstractProperty.java:268)
	at org.gradle.api.internal.provider.AbstractProperty.calculateOwnValue(AbstractProperty.java:162)
	at org.gradle.api.internal.provider.AbstractMinimalProvider.calculateOwnPresentValue(AbstractMinimalProvider.java:80)
	at org.gradle.api.internal.provider.AbstractMinimalProvider.get(AbstractMinimalProvider.java:100)
	at io.gitlab.trixnity.gradle.cargo.CargoPlugin.checkRequiredCrateTypes(CargoPlugin.kt:176)
	at io.gitlab.trixnity.gradle.cargo.CargoPlugin.applyAfterEvaluate(CargoPlugin.kt:86)
	at io.gitlab.trixnity.gradle.cargo.CargoPlugin.apply$lambda$6(CargoPlugin.kt:81)
	at io.gitlab.trixnity.gradle.cargo.CargoPlugin.apply$lambda$7(CargoPlugin.kt:78)

It looks like the plugin cannot resolve: 1) the cargo workspace properly 2) the fact that the workspace is in the parent folder. I tried symlinking the workspace itself into desktop, but that did also through errno=2 file not found errors.
Any idea what is going wrong here?