From ae1f0b96e3a5e18c3fcc8bfef74fa09b15b42213 Mon Sep 17 00:00:00 2001
From: Noratrieb <48135649+Noratrieb@users.noreply.github.com>
Date: Sun, 8 Sep 2024 12:31:28 +0200
Subject: [PATCH] hacky way to configure parallelism

---
 README.md    |  3 ++-
 src/build.rs | 12 ++++++++----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index f2af977..743ce38 100644
--- a/README.md
+++ b/README.md
@@ -5,12 +5,13 @@ A webapp that checks which Rust targets build at any nightly.
 It does this by executing `cargo build --release -Zbuild-std=core` for every target and every nightly and displaying the result.
 
 There's a background job that continously builds every target for every target that it hasn't built yet.
-It does this in parallel, using half of the available threads.
+It does this in parallel, using half of the available threads (or `DOES_IT_BUILD_PARALLEL_JOBS`).
 
 
 ## Configuration
 
 - `DB_PATH`: Path to SQlite DB to store the results
+- `DOES_IT_BUILD_PARALLEL_JOBS`: Parallel build jobs, defaults to cores/2.
 
 ## Deployment
 
diff --git a/src/build.rs b/src/build.rs
index b4fd52a..c76d7bc 100644
--- a/src/build.rs
+++ b/src/build.rs
@@ -172,10 +172,14 @@ pub async fn build_every_target_for_toolchain(
         .await
         .wrap_err("failed to get targets")?;
 
-    let concurrent = std::thread::available_parallelism()
-        .unwrap_or(NonZeroUsize::new(2).unwrap())
-        .get()
-        / 2;
+    let concurrent = std::env::var("DOES_IT_BUILD_PARALLEL_JOBS")
+        .map(|jobs| jobs.parse().unwrap())
+        .unwrap_or_else(|_| {
+            std::thread::available_parallelism()
+                .unwrap_or(NonZeroUsize::new(2).unwrap())
+                .get()
+                / 2
+        });
 
     let results = futures::stream::iter(
         targets