From 687d613a71b62ee2dc4b1cbb6c456646240a29f3 Mon Sep 17 00:00:00 2001
From: Philip Metzger <philipmetzger@bluewin.ch>
Date: Wed, 24 Jul 2024 20:16:03 +0200
Subject: [PATCH] run: Treat `jj run -j0 <command>` as use all available cores

Waleed noticed this is #3638.
---
 cli/src/commands/run.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cli/src/commands/run.rs b/cli/src/commands/run.rs
index cbcab0296f1..6e9c94e429f 100644
--- a/cli/src/commands/run.rs
+++ b/cli/src/commands/run.rs
@@ -59,7 +59,7 @@ pub fn cmd_run(ui: &mut Ui, command: &CommandHelper, args: &RunArgs) -> Result<(
     // 2. the amount of cores available.
     // 3. a single job, if all of the above fails.
     let _jobs = match args.jobs {
-        Some(0) => return Err(user_error("must pass at least one job")),
+        Some(0) => std::thread::available_parallelism().map(|t| t.into()).ok(),
         Some(jobs) => Some(jobs),
         None => std::thread::available_parallelism().map(|t| t.into()).ok(),
     }