From e2c1b44cdbdd80c89a468c5096ceaea06e261c2d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hans=20M=C3=BCndelein?= <hm@zrch.com>
Date: Sat, 25 Jul 2026 13:29:26 +0200
Subject: [PATCH] Fix sccache coflict

---
 devenv-rust.nix | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/devenv-rust.nix b/devenv-rust.nix
index d15ab1a..911789f 100644
--- a/devenv-rust.nix
+++ b/devenv-rust.nix
@@ -26,6 +26,14 @@
     vulkan-tools
   ];
   env.RUSTC_WRAPPER = "sccache";
+  # Per-user sccache server socket. On the default shared TCP port (4226)
+  # the first user's server performs every rustc write for every user, so a
+  # second user's builds die with EACCES in their own target/ dir.
+  enterShell = ''
+    sccache_dir="''${XDG_RUNTIME_DIR:-/tmp/sccache-$(id -u)}"
+    mkdir -p "$sccache_dir"
+    export SCCACHE_SERVER_UDS="$sccache_dir/sccache.sock"
+  '';
   # https://devenv.sh/languages/
   languages.rust = {
     enable = true;