Update deploy scripts' git commands

Author: kdkasad

ci/vulcan/build-for-ci.sh

@@ -1,33 +1,36 @@
 #!/usr/bin/env bash
 
 # Build the webring at a particular commit hash and put it in the `/dev/shm/webring-ci` directory.
-# 
+#
 # The working directory is expected to be the highest directory of the git repo (~/webring)
 
 set -e
 
 if [ $# -ne 1 ]; then
-  echo Expected one argument for the commit hash
+  echo Error: expected one argument for the commit hash >&2
   exit 1
 fi
 
-HASH=$1
+HASH="$1"
 
 # Set up the testing directory in tmpfs
 
 CI_PATH=/dev/shm/webring-ci
 
-# Create the directory if it's not already created
-if ! [ -d $CI_PATH ]; then
-  # Prevent other users from deleting/modifying our directory
-  mkdir $CI_PATH --mode=700
+# Ensure there isn't a deployment already running
+if [ -d "$CI_PATH" ]; then
+    echo "Error: $CI_PATH exists. Is there a CI job already running?" >&2
+    exit 1
 fi
 
+# Prevent other users from deleting/modifying our directory
+mkdir "$CI_PATH" --mode=700
+
 # Checkout the commit into the testing directory
 # Use `--work-tree` to copy the code into the testing directory instead of the deployment directory. This doesn't copy `.git`.
-git fetch --all
-git --work-tree $CI_PATH checkout $HASH -- .
-cd $CI_PATH
+git fetch origin "$HASH"
+git -c advice.detachedHead=false --work-tree "$CI_PATH" restore --source="$HASH" --worktree -- :/
+cd "$CI_PATH"
 
 # Build the flake
 nix build

ci/vulcan/deploy.sh

@@ -5,15 +5,15 @@
 set -e
 
 if [ $# -ne 1 ]; then
-  echo Expected one argument for the commit hash
+  echo Error: expected one argument for the commit hash >&2
   exit 1
 fi
 
 HASH=$1
 
 # Fetch and checkout the commit
-git fetch --all
-git checkout $HASH
+git fetch origin "$HASH"
+git -c advice.detachedHead=false checkout --force "$HASH"
 
 # Reload home manager — Automatically rebuilds the webring and restarts the systemd unit.
 home-manager switch