diff --git a/install.sh b/install.sh
index 92f38f3..966e4d8 100755
--- a/install.sh
+++ b/install.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 set -eux
 
 export DEBIAN_FRONTEND=noninteractive
diff --git a/scripts/add_repo.sh b/scripts/add_repo.sh
old mode 100644
new mode 100755
index b2abaad..62baeec
--- a/scripts/add_repo.sh
+++ b/scripts/add_repo.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 set -eux
 
 echo "Enabling universe repo.."
diff --git a/scripts/add_users.sh b/scripts/add_users.sh
old mode 100644
new mode 100755
index 2271948..c4b673e
--- a/scripts/add_users.sh
+++ b/scripts/add_users.sh
@@ -1,3 +1,7 @@
+#!/bin/bash
+
+set -eux
+
 source vars.sh
 
 echo "Creating admin account, $ADMIN_USER..."
diff --git a/scripts/code.sh b/scripts/code.sh
old mode 100644
new mode 100755
index b3768bb..615d46a
--- a/scripts/code.sh
+++ b/scripts/code.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 set -eux
 
 echo "Installing VS Code ..."
diff --git a/scripts/codeblocks.sh b/scripts/codeblocks.sh
old mode 100644
new mode 100755
index 7328fb7..154ec26
--- a/scripts/codeblocks.sh
+++ b/scripts/codeblocks.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 set -eux
 
 # https://linuxhint.com/install-code-blocks-ubuntu/
diff --git a/scripts/copy_admin_scripts.sh b/scripts/copy_admin_scripts.sh
old mode 100644
new mode 100755
index 2ea79c5..c0d3721
--- a/scripts/copy_admin_scripts.sh
+++ b/scripts/copy_admin_scripts.sh
@@ -1,3 +1,7 @@
+#!/bin/bash
+
+set -eux
+
 source vars.sh
 
 cd $ADMIN_SCRIPTS_DIR
diff --git a/scripts/copy_dots.sh b/scripts/copy_dots.sh
old mode 100644
new mode 100755
index db5eecc..b164300
--- a/scripts/copy_dots.sh
+++ b/scripts/copy_dots.sh
@@ -1,3 +1,7 @@
+#!/bin/bash
+
+set -eux
+
 source vars.sh
 
 cd $DOTS_DIR
diff --git a/scripts/dist_upgrade.sh b/scripts/dist_upgrade.sh
old mode 100644
new mode 100755
index 7d516c3..d9172e4
--- a/scripts/dist_upgrade.sh
+++ b/scripts/dist_upgrade.sh
@@ -1,2 +1,6 @@
+#!/bin/bash
+
+set -eux
+
 apt update
 apt -y dist-upgrade
diff --git a/scripts/emacs.sh b/scripts/emacs.sh
index 15173cb..43d271c 100755
--- a/scripts/emacs.sh
+++ b/scripts/emacs.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 set -eux
 
 echo "\nInstalling Emacs ...\n"
diff --git a/scripts/geany.sh b/scripts/geany.sh
index 7a84dbd..c9f1c28 100755
--- a/scripts/geany.sh
+++ b/scripts/geany.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 set -eux
 
 echo "\nInstalling Geany ...\n"
diff --git a/scripts/google_chrome.sh b/scripts/google_chrome.sh
old mode 100644
new mode 100755
index 6f63838..6fb6b3a
--- a/scripts/google_chrome.sh
+++ b/scripts/google_chrome.sh
@@ -1,3 +1,7 @@
+#!/bin/bash
+
+set -eux
+
 echo "Installing Google Chrome.."
 
 wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
diff --git a/scripts/openjdk17.sh b/scripts/openjdk17.sh
index 942637f..00611a7 100755
--- a/scripts/openjdk17.sh
+++ b/scripts/openjdk17.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 set -eux
 
 echo "\nInstalling OpenJDK 17 ...\n"
diff --git a/scripts/openssh_server.sh b/scripts/openssh_server.sh
old mode 100644
new mode 100755
index ea5d73c..ab2e832
--- a/scripts/openssh_server.sh
+++ b/scripts/openssh_server.sh
@@ -1,3 +1,7 @@
+#!/bin/bash
+
+set -eux
+
 echo "Installing openssh-server..."
 
 apt install -y openssh-server
diff --git a/scripts/sublime.sh b/scripts/sublime.sh
index 5b7f2eb..58989ac 100755
--- a/scripts/sublime.sh
+++ b/scripts/sublime.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 set -eux
 
 # https://www.sublimetext.com/docs/linux_repositories.html#apt
diff --git a/scripts/trim.sh b/scripts/trim.sh
index f5b5e04..702c559 100755
--- a/scripts/trim.sh
+++ b/scripts/trim.sh
@@ -1,11 +1,11 @@
 #!/bin/bash
 
+set -eux
+
 # This script trims down the base Ubuntu 22.04 rootfs.
 # It removes unnecessary (for our purposes) packages like
 # thunderbird, libreoffice, rhythmbox, aisleriot etc.
 
-set -eux
-
 apt remove -y --purge \
 	aisleriot \
 	gnome-mahjongg \
diff --git a/scripts/vim.sh b/scripts/vim.sh
old mode 100644
new mode 100755
index 927763d..1840281
--- a/scripts/vim.sh
+++ b/scripts/vim.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 set -eux
 
 echo "\nInstalling Vim ...\n"
diff --git a/vars.sh b/vars.sh
old mode 100644
new mode 100755
index 253f309..5a423ac
--- a/vars.sh
+++ b/vars.sh
@@ -1,3 +1,7 @@
+#!/bin/bash
+
+set -eux
+
 DOTS_DIR="dots"
 SCRIPTS_DIR="scripts"
 ADMIN_SCRIPTS_DIR="adm"
@@ -10,3 +14,6 @@ TEAM_USER="contestant"
 TEAM_PASSWORD='$1$92hYmWFk$qPeMP85ThFuzlKbdgh3cu0'
 # encrypted with $(openssl passwd -1 PLAINTEXTPASSWORD)
 
+MOCK_USER="mock"
+MOCK_PASSWORD='$1$MzrwRNfh$km8LUveoj/rZZDZiEA8PB1'
+# encrypted with $(openssl passwd -1 'PLAINTEXTPASSWORD')