'MQTT Transmitter now references modules/MQTTtransmitter.modl'

'new transmitter only runs on fresh volume so delete volume if you need to install a new module'

gw-build/Dockerfile

@@ -20,6 +20,10 @@ ARG SUPPLEMENTAL_MQTTTRANSMISSIONNIGHTLY_DOWNLOAD_URL="https://ignition-modules-
 ARG SUPPLEMENTAL_MQTTTRANSMISSIONNIGHTLY_DOWNLOAD_SHA256="notused"
 ARG SUPPLEMENTAL_MODULES
 
+# Local MQTT module built/placed in the sibling `modules/` directory (see the
+# "modules" additional build context wired up in docker-compose.yml)
+ARG SUPPLEMENTAL_MQTT_LOCAL_MODULE=MQTTtransmitter.modl
+
 # Set working directory for this prep image and ensure that exits from sub-shells bubble up and report an error
 WORKDIR /root
 SHELL [ "/usr/bin/env", "-S", "bash", "-euo", "pipefail", "-O", "inherit_errexit", "-c" ]
@@ -28,6 +32,9 @@ SHELL [ "/usr/bin/env", "-S", "bash", "-euo", "pipefail", "-O", "inherit_errexit
 COPY --chmod=0755 retrieve-modules.sh .
 RUN if [ -n "${SUPPLEMENTAL_MODULES:-}" ]; then ./retrieve-modules.sh -m "${SUPPLEMENTAL_MODULES}"; fi
 
+# Pull in the MQTT module straight from the local modules/ folder
+COPY --from=modules ${SUPPLEMENTAL_MQTT_LOCAL_MODULE} ./
+
 # Set CERTIFICATES/EULAS acceptance in gateway backup config db
 COPY *.gwbk ./
 COPY --chmod=0755 register-module.sh register-password.sh ./