chore: fix ci

source/_posts/2021/installing-arch-linux.md

@@ -252,6 +252,14 @@ on the host machine:
 ssh-copy-id <user>@<ip>
 ```
 
+```bash:$HOME/.ssh/rc
+if [ ! -S ~/.ssh/ssh_auth_sock ] && [ -S "$SSH_AUTH_SOCK" ]; then
+  ln -sf $SSH_AUTH_SOCK ~/.ssh/ssh_auth_sock
+fi
+```
+
+See also: [Happy ssh agent forwarding for tmux/screen · Reboot and Shine](https://werat.dev/blog/happy-ssh-agent-forwarding/)
+
 ## AUR
 
 ```bash
@@ -568,19 +576,19 @@ restic backup --tag system -v \
   --exclude /var/lib/docker/overlay2 \
   / /boot
 
-# ftl
-restic backup --tag ftl -v \
-  /mnt/ftl
-
 # data
 restic backup --tag data -v \
   --exclude 'appdata_*/preview' \
   --exclude 'appdata_*/dav-photocache' \
   /mnt/data
 
+# prune
 restic forget --prune --group-by tags \
-  --keep-daily 7 --keep-weekly 3 --keep-monthly 3
+  --keep-within-daily 7d \
+  --keep-within-weekly 1m \
+  --keep-within-monthly 3m
 
+# verify
 restic check
 ```