Take 4

Dockerfile

@@ -1,11 +1,11 @@
-FROM busybox as platform_determiner
+FROM busybox AS platform_determiner
 ARG TARGETPLATFORM
 ARG BINARY_NAME
 WORKDIR /app
 COPY /target /app/target
 RUN case "$TARGETPLATFORM" in \
-      "linux/amd64") BINARY_PATH="target/release/${BINARY_NAME}" ;; \
-      "linux/arm64") BINARY_PATH="target/aarch64-unknown-linux-musl/release/${BINARY_NAME}" ;; \
+      "linux/amd64") BINARY_PATH="/app/target/release/${BINARY_NAME}" ;; \
+      "linux/arm64") BINARY_PATH="/target/aarch64-unknown-linux-musl/release/${BINARY_NAME}" ;; \
       *) exit 1 ;; \
     esac && \
     mv "$BINARY_PATH" /usr/local/bin/${BINARY_NAME}