1. Try a fix for losetup/mkfs.ext4 errors

2. Add a couple of useful packages
3. Change grep to use -e syntax

build-docker.sh

@@ -8,7 +8,7 @@ DOCKER="docker"
 # Ensure that any config variables we passed in are written to an env_file
 # so invocations in subsquent shells preserve these values
 # Add || true so passing no custom vars doesn't bork up execution
-printenv | grep 'FWVERSION=\|SERIAL=\|ROOTUSER\|ROOTUSERPASS' || true > "$DIR/.customvars"
+printenv | grep -e FWVERSION -e SERIAL -e ROOTUSER -e ROOTUSERPASS || true > "$DIR/.customvars"
 
 if ! ${DOCKER} ps >/dev/null 2>&1; then
 	DOCKER="sudo docker"

export-image/prerun.sh

@@ -39,8 +39,27 @@ BOOT_LENGTH=$(echo "$PARTED_OUT" | grep -e '^1:' | cut -d':' -f 4 | tr -d B)
 ROOT_OFFSET=$(echo "$PARTED_OUT" | grep -e '^2:' | cut -d':' -f 2 | tr -d B)
 ROOT_LENGTH=$(echo "$PARTED_OUT" | grep -e '^2:' | cut -d':' -f 4 | tr -d B)
 
+# Allow errors, losetup might fail the first time
+set +e
 BOOT_DEV=$(losetup --show -f -o "${BOOT_OFFSET}" --sizelimit "${BOOT_LENGTH}" "${IMG_FILE}")
+sleep 5
+set -e
+
+# Should work now
+BOOT_DEV=$(losetup --show -f -o "${BOOT_OFFSET}" --sizelimit "${BOOT_LENGTH}" "${IMG_FILE}")
+
+# Allow errors, losetup might fail the first time
+set +e
 ROOT_DEV=$(losetup --show -f -o "${ROOT_OFFSET}" --sizelimit "${ROOT_LENGTH}" "${IMG_FILE}")
+sleep 5
+set -e
+
+# Should work now
+ROOT_DEV=$(losetup --show -f -o "${ROOT_OFFSET}" --sizelimit "${ROOT_LENGTH}" "${IMG_FILE}")
+
+# Sleep for a bit for the mounted loop devices to show up
+sleep 5
+
 echo "/boot: offset $BOOT_OFFSET, length $BOOT_LENGTH"
 echo "/:     offset $ROOT_OFFSET, length $ROOT_LENGTH"
 

stage2/04-custom-tweaks/00-packages

@@ -1 +1,3 @@
-python3-pip
+python3-pip
+v4l2loopback-dkms
+ffmpeg