feat(app): configurable Modrinth endpoints through .env files (#4015)

packages/app-lib/build.rs

@@ -4,12 +4,31 @@ use std::process::{Command, exit};
 use std::{env, fs};
 
 fn main() {
+    println!("cargo::rerun-if-changed=.env");
     println!("cargo::rerun-if-changed=java/gradle");
     println!("cargo::rerun-if-changed=java/src");
     println!("cargo::rerun-if-changed=java/build.gradle.kts");
     println!("cargo::rerun-if-changed=java/settings.gradle.kts");
     println!("cargo::rerun-if-changed=java/gradle.properties");
 
+    set_env();
+    build_java_jars();
+}
+
+fn set_env() {
+    for (var_name, var_value) in
+        dotenvy::dotenv_iter().into_iter().flatten().flatten()
+    {
+        if var_name == "DATABASE_URL" {
+            // The sqlx database URL is a build-time detail that should not be exposed to the crate
+            continue;
+        }
+
+        println!("cargo::rustc-env={var_name}={var_value}");
+    }
+}
+
+fn build_java_jars() {
     let out_dir =
         dunce::canonicalize(PathBuf::from(env::var_os("OUT_DIR").unwrap()))
             .unwrap();
@@ -37,6 +56,7 @@ fn main() {
         .current_dir(dunce::canonicalize("java").unwrap())
         .status()
         .expect("Failed to wait on Gradle build");
+
     if !exit_status.success() {
         println!("cargo::error=Gradle build failed with {exit_status}");
         exit(exit_status.code().unwrap_or(1));