From 608565bbc94b4fc1d9021caf147f5723fb873683 Mon Sep 17 00:00:00 2001
From: emilylange <git@emilylange.de>
Date: Mon, 16 Feb 2026 20:48:34 +0100
Subject: [PATCH] nixos/prometheus: fix `cfg.enableAgentMode`

Since Prometheus v3.0.0, the flag to run Prometheus in the Agent mode is
called --agent instead of --enable-feature=agent.

See https://prometheus.io/docs/prometheus/3.9/migration/
and https://prometheus.io/docs/prometheus/3.9/prometheus_agent/
---
 nixos/modules/services/monitoring/prometheus/default.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nixos/modules/services/monitoring/prometheus/default.nix b/nixos/modules/services/monitoring/prometheus/default.nix
index 4ad13d9eac08..d85825be5057 100644
--- a/nixos/modules/services/monitoring/prometheus/default.nix
+++ b/nixos/modules/services/monitoring/prometheus/default.nix
@@ -97,7 +97,7 @@ let
     ++ (
       if (cfg.enableAgentMode) then
         [
-          "--enable-feature=agent"
+          "--agent"
         ]
       else
         [