Distillation

Date: Sep 8, 2026

• 🔴 (04:02) User stated that systemd-run --expand-environment= will be switched to enabled by default for --scope in a future release; currently it defaults to enabled except with --scope, where it is disabled for backward compatibility.
• 🟡 (04:02) systemd-run can create transient .service or .scope units and transient .path, .socket, or .timer units that trigger a service.
• 🟡 (04:02) A transient service runs asynchronously in a clean, detached environment with the service manager as parent; a transient scope, enabled with --scope, is launched by systemd-run, inherits the caller’s environment, and executes synchronously.
• 🟡 (04:02) systemd-run --pty/-t connects standard input, output, and error to a pseudo-TTY, supporting interactive programs such as shells.
• 🟡 (04:02) systemd-run --shell/-S is shorthand for --pty --same-dir --wait --collect --service-type=exec $SHELL.
• 🟡 (04:02) systemd-run --wait waits for the transient service to terminate and reports runtime plus main-process exit code/status; it cannot be combined with --no-block, --scope, or path/socket/timer options.
• 🟡 (04:02) systemd-run --no-block only verifies and enqueues unit startup rather than waiting for startup completion, and cannot be combined with --wait.