hacky way to configure parallelism

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
 

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()
+    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;
+                / 2
+        });
 
     let results = futures::stream::iter(
         targets