diff --git a/.gitmodules b/.gitmodules
index b001b028..b87a009a 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -3570,3 +3570,9 @@
 [submodule "2024/03/17/mach-nix"]
 	path = 2024/03/17/mach-nix
 	url = https://github.com/DavHau/mach-nix
+[submodule "2024/03/18/hydra"]
+	path = 2024/03/18/hydra
+	url = https://github.com/NixOS/hydra
+[submodule "2024/03/18/guix-cuirass"]
+	path = 2024/03/18/guix-cuirass
+	url = https://git.savannah.gnu.org/git/guix/guix-cuirass.git
diff --git a/2024/03/18/guix-cuirass b/2024/03/18/guix-cuirass
new file mode 160000
index 00000000..7bcd3d07
--- /dev/null
+++ b/2024/03/18/guix-cuirass
@@ -0,0 +1 @@
+Subproject commit 7bcd3d079f0ec45ac50f0dbc14eb4ec68c6a6b53
diff --git a/2024/03/18/hydra b/2024/03/18/hydra
new file mode 160000
index 00000000..8f56209b
--- /dev/null
+++ b/2024/03/18/hydra
@@ -0,0 +1 @@
+Subproject commit 8f56209bd6f3b9ec53d50a23812a800dee7a1969