diff --git a/build-android-app.sh b/build-android-app.sh
index 26ae47d..865d2d5 100755
--- a/build-android-app.sh
+++ b/build-android-app.sh
@@ -1,11 +1,11 @@
 #!/bin/sh
 
-set -ex 
+set -e 
 
 CONTAINERRUNTIMES='docker podman nerdctl'
 for CONTAINERRUNTIME in $CONTAINERRUNTIMES /
 do
-    type $CONTAINERRUNTIME 2>/dev/null && break
+    type $CONTAINERRUNTIME >/dev/null 2>/dev/null && break
     test "$CONTAINERRUNTIME" = / && { 
         echo "install a container runtime (e.g ${CONTAINERRUNTIMES//\ /\/})" >&2
         exit 2
@@ -15,7 +15,7 @@ done
 HASHES='md5sum cksum sha1sum base64 uuencode'
 for HASH in $HASHES /
 do
-    type $HASH 2>/dev/null && break
+    type $HASH >/dev/null 2>/dev/null && break
     test "$HASH" = / && { 
         echo "install checksum (e.g ${HASHES//\ /\/})" >&2
         exit 3
@@ -26,32 +26,45 @@ DockerfileContent(){
 cat << 'DOCKERFILEEOF'
 FROM debian:latest
 RUN apt-get update -y && apt-get install -y make openjdk-17-jdk-headless unzip zip wget curl whiptail
-ENTRYPOINT ["/bin/bash","-c","make"]
 ENV JAVA_HOME="/usr/lib/jvm/java-17-openjdk-amd64/"
 ENV ANDROID_SDK_ROOT="/app/android-sdk"
 ENV BUILD_TOOLS_LATEST="$ANDROID_SDK_ROOT/cmdline-tools/latest"
 ENV PATH="$BUILD_TOOLS_LATEST/bin:$PATH"
 ENV LIBRARY_PATH="$LIBRARY_PATH:$BUILD_TOOLS_LATEST/lib"
+CMD ["make","--trace"]
 DOCKERFILEEOF
 }
 
 diff Dockerfile <(DockerfileContent) 2>/dev/null > /dev/null || {
-    read -p 'reset/start Dockerfile[Y/n]' YES
-    test "$YES" = "n" && { echo "aborting..." >&2; exit 1; }
+    test -f Dockerfile && {
+        read -p 'reset/start Dockerfile[Y/n]' YES
+        test "$YES" = "n" && { echo "aborting..." >&2; exit 1; }
+    }
     DockerfileContent > Dockerfile
 }
 
 
-IMAGE=android-app:"$($HASH Dockerfile | tr -cd '[a-zA-Z0-9]' | head -c 12)"
+IMAGE=build-android-app:"$($HASH Dockerfile | tr -cd '[a-zA-Z0-9]' | head -c 12)"
 docker image inspect "$IMAGE" >/dev/null 2>/dev/null || {
   $CONTAINERRUNTIME build --tag "$IMAGE" .
 }
+#(optional) tag the latest image build
+docker tag $IMAGE build-android-app:latest
 
-$CONTAINERRUNTIME run --name build-android-app-$(date +%F--%H-%M-%S) \
+time $CONTAINERRUNTIME run --name build-android-app-$(date +%F--%H-%M-%S) \
     --workdir=/app \
     --hostname build-android-app \
     --volume ./app:/app \
     -it \
     --rm \
-    "$IMAGE"
+    "$IMAGE" "$@" | { 
+        test "$#" -eq 0 && {
+            # colur output in case this script was called without]
+            # command line arguments
+            sed 's/^Makefile:/\n\n'$'\033[0;32m''Makefile:'$'\033[0m''/g' 
+        } || {
+            # no modification else
+            cat 
+        }
+    }