From 7392da3f703ed6da17e55b5f5963dd37e2e2f5e2 Mon Sep 17 00:00:00 2001
From: Jo <10510431+j178@users.noreply.github.com>
Date: Thu, 16 Jul 2026 11:15:30 +0800
Subject: [PATCH] Share Julia depot cache

---
 crates/prek-consts/src/env_vars.rs |  3 +++
 crates/prek/src/languages/julia.rs | 18 ++++++++++++++++--
 crates/prek/src/languages/mod.rs   |  2 +-
 crates/prek/src/store.rs           |  1 +
 4 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/crates/prek-consts/src/env_vars.rs b/crates/prek-consts/src/env_vars.rs
index a60475970..779534a45 100644
--- a/crates/prek-consts/src/env_vars.rs
+++ b/crates/prek-consts/src/env_vars.rs
@@ -173,6 +173,9 @@ impl EnvVars {
     // Coursier related
     pub const COURSIER_CACHE: &'static str = "COURSIER_CACHE";
 
+    // Julia related
+    pub const JULIA_DEPOT_PATH: &'static str = "JULIA_DEPOT_PATH";
+
     // Ruby related
     pub const PREK_RUBY_MIRROR: &'static str = "PREK_RUBY_MIRROR";
     pub const GEM_HOME: &'static str = "GEM_HOME";
diff --git a/crates/prek/src/languages/julia.rs b/crates/prek/src/languages/julia.rs
index a44f174c7..4bc32f493 100644
--- a/crates/prek/src/languages/julia.rs
+++ b/crates/prek/src/languages/julia.rs
@@ -1,8 +1,10 @@
+use std::ffi::OsString;
 use std::path::Path;
 use std::process::Stdio;
 use std::sync::Arc;
 
 use anyhow::{Context, Result};
+use prek_consts::env_vars::EnvVars;
 use tracing::debug;
 
 use crate::cli::reporter::HookInstallReporter;
@@ -11,11 +13,17 @@ use crate::hook::{Hook, InstallInfo, InstalledHook};
 use crate::languages::LanguageBackend;
 use crate::process::Cmd;
 use crate::run::run_by_batch;
-use crate::store::Store;
+use crate::store::{CacheBucket, Store};
 
 #[derive(Debug, Copy, Clone)]
 pub(crate) struct Julia;
 
+fn depot_path(store: &Store) -> Result<OsString> {
+    let depot = store.cache_path(CacheBucket::Julia);
+    std::env::join_paths([depot.as_path(), Path::new("")])
+        .context("Failed to join Julia depot path")
+}
+
 #[async_trait::async_trait(?Send)]
 impl LanguageBackend for Julia {
     async fn install(
@@ -31,6 +39,9 @@ impl LanguageBackend for Julia {
         debug!(%hook, target = %info.env_path.display(), "Installing Julia environment");
 
         fs_err::tokio::create_dir_all(&info.env_path).await?;
+        let depot = store.cache_path(CacheBucket::Julia);
+        fs_err::tokio::create_dir_all(&depot).await?;
+        let depot_path = depot_path(store)?;
         let search_path = hook.repo_path().unwrap_or_else(|| hook.work_dir());
 
         let find_src = |names: &[&str]| {
@@ -70,6 +81,7 @@ impl LanguageBackend for Julia {
             .arg(julia_code)
             .arg("--")
             .args(&hook.additional_dependencies)
+            .env(EnvVars::JULIA_DEPOT_PATH, &depot_path)
             .check(true)
             .output()
             .await
@@ -97,7 +109,7 @@ impl LanguageBackend for Julia {
 
     async fn run(
         &self,
-        _store: &Store,
+        store: &Store,
         hook: &InstalledHook,
         filenames: &[&Path],
         reporter: &HookRunReporter,
@@ -105,6 +117,7 @@ impl LanguageBackend for Julia {
         let progress = reporter.on_run_start(hook, filenames.len());
 
         let env_dir = hook.env_path().expect("Julia must have env path");
+        let depot_path = depot_path(store)?;
 
         let mut entry = hook.entry.expect_direct().split()?;
         if let Some(repo_path) = hook.repo_path() {
@@ -121,6 +134,7 @@ impl LanguageBackend for Julia {
                 .arg(format!("--project={}", env_dir.display()))
                 .args(&entry)
                 .envs(&hook.env)
+                .env(EnvVars::JULIA_DEPOT_PATH, &depot_path)
                 .args(&hook.args)
                 .file_args(batch)
                 .check(false)
diff --git a/crates/prek/src/languages/mod.rs b/crates/prek/src/languages/mod.rs
index 9daec31d2..7aa39729f 100644
--- a/crates/prek/src/languages/mod.rs
+++ b/crates/prek/src/languages/mod.rs
@@ -222,6 +222,7 @@ impl Language {
             Self::Coursier => &[CacheBucket::Coursier],
             Self::Deno => &[CacheBucket::Deno],
             Self::Golang => &[CacheBucket::Go],
+            Self::Julia => &[CacheBucket::Julia],
             Self::Node => &[CacheBucket::Npm],
             Self::Python | Self::Pygrep => &[CacheBucket::Uv, CacheBucket::Python],
             Self::Rust => &[CacheBucket::Cargo],
@@ -233,7 +234,6 @@ impl Language {
             | Self::Dotnet
             | Self::Fail
             | Self::Haskell
-            | Self::Julia
             | Self::Lua
             | Self::Perl
             | Self::Php
diff --git a/crates/prek/src/store.rs b/crates/prek/src/store.rs
index 11a0d3885..04108480d 100644
--- a/crates/prek/src/store.rs
+++ b/crates/prek/src/store.rs
@@ -430,6 +430,7 @@ pub(crate) enum CacheBucket {
     Python,
     Cargo,
     Deno,
+    Julia,
     Npm,
     Coursier,
     Prek,