diff --git a/src/components/backend-core/Dockerfile b/src/components/backend-core/Dockerfile
index 95c08486..40a8f5a8 100644
--- a/src/components/backend-core/Dockerfile
+++ b/src/components/backend-core/Dockerfile
@@ -1,11 +1,18 @@
+# syntax=docker/dockerfile:1.7
 FROM rust:1-bookworm AS build
 WORKDIR /app/src/components/backend-core
 ARG CARGO_BUILD_JOBS=1
 ENV CARGO_BUILD_JOBS=${CARGO_BUILD_JOBS}
 COPY src/components/backend-core/Cargo.toml ./Cargo.toml
 COPY src/components/backend-core/Cargo.lock ./Cargo.lock
+RUN mkdir -p src \
+  && printf 'fn main() {}\n' > src/main.rs \
+  && cargo build --release --locked --jobs "${CARGO_BUILD_JOBS}" \
+  && rm -rf src
 COPY src/components/backend-core/src ./src
-RUN cargo build --release --jobs "${CARGO_BUILD_JOBS}"
+RUN rm -f target/release/backend-core target/release/backend-core.d \
+  && find target/release/.fingerprint -maxdepth 1 -type d -name 'unidesk-backend-core-*' -exec rm -rf {} + \
+  && cargo build --release --locked --jobs "${CARGO_BUILD_JOBS}"
 
 FROM postgres:16-bookworm
 RUN apt-get update \
diff --git a/src/components/backend-core/src/cli.rs b/src/components/backend-core/src/cli.rs
index b536fcbe..16d769a3 100644
--- a/src/components/backend-core/src/cli.rs
+++ b/src/components/backend-core/src/cli.rs
@@ -11,6 +11,18 @@ use tokio_tungstenite::tungstenite::Message;
 
 use crate::http::internal_fetch_json;
 
+async fn write_stdout(bytes: &[u8]) {
+    let mut stdout = tokio::io::stdout();
+    let _ = stdout.write_all(bytes).await;
+    let _ = stdout.flush().await;
+}
+
+async fn write_stderr(bytes: &[u8]) {
+    let mut stderr = tokio::io::stderr();
+    let _ = stderr.write_all(bytes).await;
+    let _ = stderr.flush().await;
+}
+
 pub async fn handle_cli() -> anyhow::Result<bool> {
     let mut args = env::args().skip(1).collect::<Vec<_>>();
     if args.is_empty() {
@@ -171,16 +183,12 @@ async fn ssh_broker_cli(args: Vec<String>) -> anyhow::Result<()> {
     loop {
         let message = tokio::select! {
             _ = &mut runtime_timer => {
-                let _ = tokio::io::stderr()
-                    .write_all(format!("unidesk ssh bridge runtime timeout after {runtime_timeout_ms}ms\n").as_bytes())
-                    .await;
+                write_stderr(format!("unidesk ssh bridge runtime timeout after {runtime_timeout_ms}ms\n").as_bytes()).await;
                 exit_code = 124;
                 break;
             }
             _ = &mut open_timer, if !opened => {
-                let _ = tokio::io::stderr()
-                    .write_all(format!("unidesk ssh bridge timed out waiting for provider session after {open_timeout_ms}ms\n").as_bytes())
-                    .await;
+                write_stderr(format!("unidesk ssh bridge timed out waiting for provider session after {open_timeout_ms}ms\n").as_bytes()).await;
                 exit_code = 255;
                 break;
             }
@@ -207,13 +215,12 @@ async fn ssh_broker_cli(args: Vec<String>) -> anyhow::Result<()> {
                     .decode(data)
                     .unwrap_or_default();
                 if parsed.get("stream").and_then(Value::as_str) == Some("stderr") {
-                    let _ = tokio::io::stderr().write_all(&bytes).await;
+                    write_stderr(&bytes).await;
                 } else {
-                    let _ = tokio::io::stdout().write_all(&bytes).await;
+                    write_stdout(&bytes).await;
                 }
             }
             "ssh.exit" => {
-                opened = true;
                 exit_code = parsed
                     .get("exitCode")
                     .and_then(Value::as_i64)
@@ -221,18 +228,17 @@ async fn ssh_broker_cli(args: Vec<String>) -> anyhow::Result<()> {
                 break;
             }
             "ssh.error" => {
-                let _ = tokio::io::stderr()
-                    .write_all(
-                        format!(
-                            "{}\n",
-                            parsed
-                                .get("message")
-                                .and_then(Value::as_str)
-                                .unwrap_or("ssh error")
-                        )
-                        .as_bytes(),
+                write_stderr(
+                    format!(
+                        "{}\n",
+                        parsed
+                            .get("message")
+                            .and_then(Value::as_str)
+                            .unwrap_or("ssh error")
                     )
-                    .await;
+                    .as_bytes(),
+                )
+                .await;
                 exit_code = 255;
                 break;
             }