Tweak armv6hf crossbuild script

Fix example typo in Dockerfile

Author: ashthespy

contrib/Dockerfile

@@ -11,7 +11,7 @@
 # $ docker run -v /tmp/librespot-build:/build librespot-cross cargo build --release --no-default-features --features "alsa-backend"
 # $ docker run -v /tmp/librespot-build:/build librespot-cross cargo build --release --target arm-unknown-linux-gnueabihf --no-default-features --features "alsa-backend"
 # $ docker run -v /tmp/librespot-build:/build librespot-cross cargo build --release --target arm-unknown-linux-gnueabi --no-default-features --features "alsa-backend"
-# $ docker run -v /tmp/librespot-build:/build librespot-cross docker-build-pi-armv6hf.sh
+# $ docker run -v /tmp/librespot-build:/build contrib/librespot-cross docker-build-pi-armv6hf.sh
 
 FROM debian:stretch
 

contrib/docker-build-pi-armv6hf.sh

@@ -1,8 +1,16 @@
 #!/usr/bin/env bash
 
 # Snipped and tucked from https://github.com/plietar/librespot/pull/202/commits/21549641d39399cbaec0bc92b36c9951d1b87b90
+# and further inputs from https://github.com/kingosticks/librespot/commit/c55dd20bd6c7e44dd75ff33185cf50b2d3bd79c3
 
 set -eux
+# Get alsa lib and headers
+ALSA_VER="1.0.25-4"
+DEPS=( \
+  "http://mirrordirector.raspbian.org/raspbian/pool/main/a/alsa-lib/libasound2_${ALSA_VER}_armhf.deb" \
+  "http://mirrordirector.raspbian.org/raspbian/pool/main/a/alsa-lib/libasound2-dev_${ALSA_VER}_armhf.deb" \
+)
+
 # Collect Paths
 SYSROOT="/pi-tools/arm-bcm2708/arm-bcm2708hardfp-linux-gnueabi/arm-bcm2708hardfp-linux-gnueabi/sysroot"
 GCC="/pi-tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin"
@@ -18,16 +26,11 @@ export TARGET_CC="$GCC/arm-linux-gnueabihf-gcc"
 echo -e '#!/bin/bash' "\n$TARGET_CC --sysroot $SYSROOT \"\$@\"" > $GCC_SYSROOT
 chmod +x $GCC_SYSROOT
 
-# get alsa lib and headers
-ALSA_VER="1.0.25-4"
-ALSA_LIB="libasound2_${ALSA_VER}_armhf.deb"
-ALSA_DEV_LIB="libasound2-dev_${ALSA_VER}_armhf.deb"
-
-curl -OL "http://mirrordirector.raspbian.org/raspbian/pool/main/a/alsa-lib/$ALSA_LIB"
-dpkg -x $ALSA_LIB $SYSROOT
-curl -OL "http://mirrordirector.raspbian.org/raspbian/pool/main/a/alsa-lib/$ALSA_DEV_LIB"
-dpkg -x $ALSA_DEV_LIB $SYSROOT
-
+# Add extra target dependencies to our rpi sysroot
+for path in "${DEPS[@]}"; do
+  curl -OL $path
+  dpkg -x $(basename $path) $SYSROOT
+done
 
 # i don't why this is neccessary
 # ln -s ld-linux.so.3 $SYSROOT/lib/ld-linux-armhf.so.3