diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 53190efe4..acc57b3e6 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -95,8 +95,7 @@ build:raspbian:armv6l:
   variables:
     DOCKER_IMAGE_DEV: villas/node-dev-raspbian
     CMAKE_OPTS: -DWITH_NODE_INFINIBAND=OFF
-  only:
-  - master
+  when: manual
 
 build:debian-multiarch:armhf:
   extends: build:fedora:x86_64
diff --git a/lib/nodes/comedi.cpp b/lib/nodes/comedi.cpp
index ce6a42c52..5adaaa6c2 100644
--- a/lib/nodes/comedi.cpp
+++ b/lib/nodes/comedi.cpp
@@ -561,10 +561,10 @@ int comedi_read(struct node *n, struct sample *smps[], unsigned cnt, unsigned *r
 			const size_t raw_samples_available = bytes_available / d->sample_size;
 			const size_t villas_samples_available = raw_samples_available / d->chanlist_len;
 
-			info("there are %ld bytes available (%ld requested) => %ld villas samples",
+			info("there are %zd bytes available (%zu requested) => %zu villas samples",
 			     bytes_available, bytes_requested, villas_samples_available);
 
-			info("there are %ld kB available (%ld kB requested)",
+			info("there are %zu kB available (%zu kB requested)",
 			     bytes_available / 1024, bytes_requested / 1024);
 
 			if (cnt > villas_samples_available)
@@ -582,7 +582,7 @@ int comedi_read(struct node *n, struct sample *smps[], unsigned cnt, unsigned *r
 				smps[i]->length = d->chanlist_len;
 
 				if (smps[i]->capacity < d->chanlist_len) {
-					error("Sample has insufficient capacity: %d < %ld",
+					error("Sample has insufficient capacity: %d < %zd",
 					      smps[i]->capacity, d->chanlist_len);
 				}
 
@@ -611,7 +611,7 @@ int comedi_read(struct node *n, struct sample *smps[], unsigned cnt, unsigned *r
 				memmove(c->buf, c->bufptr, bytes_left);
 			}
 
-			info("consumed %ld bytes", bytes_consumed);
+			info("consumed %zd bytes", bytes_consumed);
 
 			/* Start at the beginning again */
 			c->bufptr = c->buf;
@@ -857,7 +857,7 @@ int comedi_write(struct node *n, struct sample *smps[], unsigned cnt, unsigned *
 	else {
 		struct timespec now = time_now();
 		if (time_delta(&d->last_debug, &now) >= 1) {
-			debug(LOG_COMEDI | 2, "Comedi write buffer: %4ld villas samples (%2.0f%% of buffer)",
+			debug(LOG_COMEDI | 2, "Comedi write buffer: %4zd villas samples (%2.0f%% of buffer)",
 			      villas_samples_in_buffer,
 			      (100.0f * villas_samples_in_buffer / buffer_capacity_villas));
 
@@ -870,7 +870,7 @@ int comedi_write(struct node *n, struct sample *smps[], unsigned cnt, unsigned *
 	while (villas_samples_written < cnt) {
 		struct sample *sample = smps[villas_samples_written];
 		if (sample->length != d->chanlist_len)
-			error("Value count in sample (%d) != configured output channels (%ld)",
+			error("Value count in sample (%d) != configured output channels (%zd)",
 			      sample->length, d->chanlist_len);
 
 		d->bufptr = d->buffer;
diff --git a/packaging/docker/CMakeLists.txt b/packaging/docker/CMakeLists.txt
index 8efb4d05e..7f8957e15 100644
--- a/packaging/docker/CMakeLists.txt
+++ b/packaging/docker/CMakeLists.txt
@@ -36,7 +36,7 @@ set(DOCKER_RUN_OPTS
 	--volume \"${PROJECT_SOURCE_DIR}:/villas\"
 )
 
-foreach(SUFFIX app dev dev-centos dev-ubuntu)
+foreach(SUFFIX app dev dev-centos dev-ubuntu dev-raspbian)
 	add_custom_target(deploy-docker-${SUFFIX}
 		COMMAND docker push ${DOCKER_IMAGE}-${SUFFIX}:${DOCKER_TAG}
 		COMMAND docker push ${DOCKER_IMAGE}-${SUFFIX}:latest
@@ -66,7 +66,7 @@ foreach(SUFFIX app dev dev-centos dev-ubuntu)
 	add_dependencies(deploy-docker-${SUFFIX} docker-${SUFFIX})
 	add_dependencies(run-docker-${SUFFIX} docker-${SUFFIX})
 endforeach()
-	
+
 # Special cases for 'docker' target
 add_custom_target(run-docker
 	COMMAND docker run ${DOCKER_RUN_OPTS} ${DOCKER_IMAGE}:${DOCKER_TAG} node -h
diff --git a/packaging/docker/Dockerfile.dev-raspbian b/packaging/docker/Dockerfile.dev-raspbian
index da1fd4139..93aa1e313 100644
--- a/packaging/docker/Dockerfile.dev-raspbian
+++ b/packaging/docker/Dockerfile.dev-raspbian
@@ -28,14 +28,16 @@ ARG VERSION=unknown
 ARG VARIANT=unknown
 
 # Toolchain
-RUN apt-get update && apt-get install -y \
+RUN apt-get update && \
+    apt-get install -y \
 	autoconf automake libtool cmake \
 	pkg-config make gcc g++\
 	git curl wget tar bzip2 \
 	protobuf-compiler protobuf-c-compiler
 
 # Dependencies
-RUN apt-get install -y\
+RUN apt-get update && \
+    apt-get install -y\
 	libssl-dev \
 	libprotobuf-dev \
 	libprotobuf-c-dev \
@@ -51,9 +53,7 @@ RUN apt-get install -y\
 	libcomedi-dev \
 	librdmacm-dev \
 	libre-dev \
-	libusb-1.0-0-dev \
-	libspdlog-dev \
-	libfmt-dev
+	libusb-1.0-0-dev
 
 ENV CC=gcc
 ENV CXX=g++
@@ -61,6 +61,22 @@ ENV CXX=g++
 # Add CMake install dir to PATH
 ENV PATH="usr/local/bin:${PATH}"
 
+# Build & Install fmtlib
+RUN cd /tmp && \
+	git clone --recursive https://github.com/fmtlib/fmt.git && \
+	mkdir -p fmt/build && cd fmt/build && \
+	git checkout 5.2.0 && \
+	cmake -DBUILD_SHARED_LIBS=1 .. && make -j$(nproc) install && \
+	rm -rf /tmp/*
+
+# Build & Install spdlog
+RUN cd /tmp && \
+	git clone --recursive https://github.com/gabime/spdlog.git && \
+	mkdir -p spdlog/build && cd spdlog/build && \
+	git checkout v1.3.1 && \
+	cmake -DCMAKE_BUILD_TYPE=Release -DSPDLOG_FMT_EXTERNAL=1 -DSPDLOG_BUILD_BENCH=OFF .. && make -j$(nproc) install && \
+	rm -rf /tmp/*
+
 # Build & Install libwebsockets
 RUN cd /tmp && \
 	git clone -b v3.1-stable https://github.com/warmcat/libwebsockets && \