Use source for sourcing instead of .

It improves readability according to some..

build-inside-vm.sh

@@ -162,7 +162,7 @@ function main() {
   setup_disk
   bootstrap
   # shellcheck source=images/base.sh
-  . "${ORIG_PWD}/images/base.sh"
+  source "${ORIG_PWD}/images/base.sh"
   pre
   unmount_image
 
@@ -176,10 +176,10 @@ function main() {
   fi
 
   # shellcheck source=images/common.sh
-  . "${ORIG_PWD}/images/common.sh"
+  source "${ORIG_PWD}/images/common.sh"
   for image in "${ORIG_PWD}/images/"!(base|common).sh; do
     # shellcheck source=/dev/null
-    . "${image}"
+    source "${image}"
     create_image "${IMAGE_NAME}" pre post
   done
 }

images/base.sh

@@ -61,7 +61,7 @@ EOF
 
   # enabling important services
   arch-chroot "${MOUNT}" /bin/bash -e <<EOF
-. /etc/profile
+source /etc/profile
 systemctl enable sshd
 systemctl enable haveged
 systemctl enable systemd-networkd