Hello, I notice the exact same problem still on a Guix System (!) freshly reconfigured with commit b1cabedd28b92324259875fc52ca5d52d411a026, so the kernel is 5.11.4-gnu.
In my case /tmp is just an ordinary subdirectory of /, which itself is LUKS encrypted and mounted from /dev/mapper/cryptroot. The "permission denied" occurs for ordinary users and root. Andreas
