diff --git a/.config/nvim/ftplugin/ruler.lua b/.config/nvim/ftplugin/ruler.lua
new file mode 100644
index 00000000..fc0ba12d
--- /dev/null
+++ b/.config/nvim/ftplugin/ruler.lua
@@ -0,0 +1 @@
+vim.bo.commentstring = "-- %s"
diff --git a/.config/nvim/syntax/ruler.vim b/.config/nvim/syntax/ruler.vim
index bc7359b3..73a21fab 100644
--- a/.config/nvim/syntax/ruler.vim
+++ b/.config/nvim/syntax/ruler.vim
@@ -8,7 +8,7 @@ endif
 
 syn match rulerLineComment        "--.*$"
 syn match rulerTripleDot          "\.\.\."
-syn match rulerDate               "\d\d\d\d\D\d\d\D\d\d \d\d\D\d\d\D\d\d"
+syn match rulerDate               "\d\d\d\d\D\d\d\D\d\d \d\d\D\d\d\D\(\d\d\|__\)"
 syn match rulerTag                "\s\+[a-zA-Z]\+:[^\n]*"
 
 syn region rulerBlockComment      start="{-"   end="-}"
diff --git a/nix/configurations/vanadium/home/dev.nix b/nix/configurations/vanadium/home/dev.nix
index 1aff2f4f..9a83b6d6 100644
--- a/nix/configurations/vanadium/home/dev.nix
+++ b/nix/configurations/vanadium/home/dev.nix
@@ -8,8 +8,9 @@
     # preview markdown
     pkgs.python3Packages.grip
 
-    # For nix contribution
+    # For {nix,haskell} contribution
     pkgs.gh
+    pkgs.act
     pkgs.nixfmt-rfc-style
     pkgs.nix-doc
     pkgs.nixpkgs-review
diff --git a/nix/homeModules/common/user-nixconf.nix b/nix/homeModules/common/user-nixconf.nix
index c7b11124..a3d867da 100644
--- a/nix/homeModules/common/user-nixconf.nix
+++ b/nix/homeModules/common/user-nixconf.nix
@@ -25,8 +25,7 @@
         "nix-command"
         "flakes"
       ];
-      keep-outputs = true;
-      keep-derivations = true;
+      keep-outputs = false; # Build time derivations and sources
     };
 
     registry.flakies = {
diff --git a/nix/packages/by-name/ruler/package.nix b/nix/packages/by-name/ruler/package.nix
index 746406e9..eae02c50 100644
--- a/nix/packages/by-name/ruler/package.nix
+++ b/nix/packages/by-name/ruler/package.nix
@@ -12,8 +12,8 @@
       domain = "git.confusedcompiler.org";
       owner = "leana8959";
       repo = "ruler";
-      rev = "a598cd3f68d12ed4787f4caf206499e188d44172";
-      hash = "sha256-PP+aMXqGjym9De50Vw8B131iAwRvoRZKk+/L9JHDoLM=";
+      rev = "03f7b0bb545a59ddc031c08879eaf7e08dea1bef";
+      hash = "sha256-ZNE2IR9f9zDS1t10bHqabXQiAq9aibfeQOo1pJtKUn0=";
     })
     {};