[PATCH] Documentation: explain Nix using too many cores

[Alyssa Ross <hi@alyssa.is>]

This is confusing to people, and will be especially so if Spectrum is
the first big Nix build they've done, which is not unlikely.

Signed-off-by: Alyssa Ross <hi@alyssa.is>
---
 Documentation/installation/getting-spectrum.adoc | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Documentation/installation/getting-spectrum.adoc b/Documentation/installation/getting-spectrum.adoc
index 3620c79..29803aa 100644
--- a/Documentation/installation/getting-spectrum.adoc
+++ b/Documentation/installation/getting-spectrum.adoc
@@ -2,7 +2,7 @@
 :page-parent: Build and Run
 :page-nav_order: 2
 
-// SPDX-FileCopyrightText: 2022-2023 Alyssa Ross <hi@alyssa.is>
+// SPDX-FileCopyrightText: 2022-2024 Alyssa Ross <hi@alyssa.is>
 // SPDX-License-Identifier: GFDL-1.3-no-invariants-or-later OR CC-BY-SA-4.0
 
 To get Spectrum, you need to build it from source.  As long as you're
@@ -16,6 +16,13 @@ TIP: Before you start, consider setting up the
 xref:binary-cache.adoc[Spectrum binary cache], which will save you a
 lot of time waiting for builds.
 
+TIP: If you encounter build failures, especially timeouts or
+out-of-memory (OOM) kills, Nix might be configured to run too many
+builds at once, with too many cores per build.  See Nix's
+documentation for
+https://nix.dev/manual/nix/2.24/advanced-topics/cores-vs-jobs.html[tuning
+cores and jobs].
+
 == Trying Spectrum
 
 If you want to try Spectrum out to get a feel for it, without

base-commit: 6e9c1f7967a44206e8f70d1d20e0f4e71987bed8
-- 
2.45.2