diff --git a/nixos/tests/os-prober.nix b/nixos/tests/os-prober.nix
index 8f3e2494047c..22e720824c80 100644
--- a/nixos/tests/os-prober.nix
+++ b/nixos/tests/os-prober.nix
@@ -8,7 +8,7 @@ let
       ${parted}/bin/parted --script /dev/vda mklabel msdos
       ${parted}/sbin/parted --script /dev/vda -- mkpart primary ext2 1M -1s
       mkdir /mnt
-      ${e2fsprogs}/bin/mkfs.ext4 /dev/vda1
+      ${e2fsprogs}/bin/mkfs.ext4 -O '^metadata_csum_seed' /dev/vda1
       ${util-linux}/bin/mount -t ext4 /dev/vda1 /mnt
 
       if test -e /mnt/.debug; then
@@ -83,6 +83,8 @@ in {
           docbook5
           docbook_xsl_ns
           grub2
+          kbd
+          kbd.dev
           kmod.dev
           libarchive
           libarchive.dev
diff --git a/pkgs/build-support/vm/default.nix b/pkgs/build-support/vm/default.nix
index 403bc9b1d2da..5cc107d2c4a8 100644
--- a/pkgs/build-support/vm/default.nix
+++ b/pkgs/build-support/vm/default.nix
@@ -1018,7 +1018,7 @@ rec {
         url = "https://snapshot.debian.org/archive/debian/20221126T084953Z/dists/buster/main/binary-i386/Packages.xz";
         hash = "sha256-n9JquhtZgxw3qr9BX0MQoY3ZTIHN0dit+iru3DC31UY=";
       };
-      urlPrefix = "mirror://debian";
+      urlPrefix = "https://snapshot.debian.org/archive/debian/20221126T084953Z";
       packages = commonDebianPackages;
     };
 
@@ -1029,7 +1029,7 @@ rec {
         url = "https://snapshot.debian.org/archive/debian/20221126T084953Z/dists/buster/main/binary-amd64/Packages.xz";
         hash = "sha256-YukIIB3u87jgp9oudwklsxyKVKjSL618wFgDSXiFmjU=";
       };
-      urlPrefix = "mirror://debian";
+      urlPrefix = "https://snapshot.debian.org/archive/debian/20221126T084953Z";
       packages = commonDebianPackages;
     };
 
@@ -1040,7 +1040,7 @@ rec {
         url = "https://snapshot.debian.org/archive/debian/20230131T034648Z/dists/bullseye/main/binary-i386/Packages.xz";
         hash = "sha256-z9eG7RlvelEnZAaeCfIO+XxTZVL3d+zTA7ShU43l/pw=";
       };
-      urlPrefix = "mirror://debian";
+      urlPrefix = "https://snapshot.debian.org/archive/debian/20230131T034648Z";
       packages = commonDebianPackages;
     };
 
@@ -1051,7 +1051,7 @@ rec {
         url = "https://snapshot.debian.org/archive/debian/20230131T034648Z/dists/bullseye/main/binary-amd64/Packages.xz";
         hash = "sha256-mz0eCWdn6uWt40OxsSPheHzEnMeLE52yR/vpb48/VF0=";
       };
-      urlPrefix = "mirror://debian";
+      urlPrefix = "https://snapshot.debian.org/archive/debian/20230131T034648Z";
       packages = commonDebianPackages;
     };
   };