From 4f706ae8d5877b09520e1ebc616165cac3c499e2 Mon Sep 17 00:00:00 2001
From: Weihang Lo <me@weihanglo.tw>
Date: Wed, 2 Mar 2022 19:41:31 +0800
Subject: [PATCH] Wrap an error context for determining the amount of
 parallelism

---
 src/cargo/core/compiler/build_config.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/cargo/core/compiler/build_config.rs b/src/cargo/core/compiler/build_config.rs
index 54b2fd9b12c..31cd3e3da53 100644
--- a/src/cargo/core/compiler/build_config.rs
+++ b/src/cargo/core/compiler/build_config.rs
@@ -1,7 +1,7 @@
 use crate::core::compiler::CompileKind;
 use crate::util::interning::InternedString;
 use crate::util::{CargoResult, Config, RustfixDiagnosticServer};
-use anyhow::bail;
+use anyhow::{bail, Context as _};
 use cargo_util::ProcessBuilder;
 use serde::ser;
 use std::cell::RefCell;
@@ -73,7 +73,9 @@ impl BuildConfig {
         }
         let jobs = match jobs.or(cfg.jobs) {
             Some(j) => j,
-            None => available_parallelism()?.get() as u32,
+            None => available_parallelism()
+                .context("failed to determine the amount of parallelism available")?
+                .get() as u32,
         };
         if jobs == 0 {
             anyhow::bail!("jobs may not be 0");