[ext] test for em module needed by dronecan (#3444)

* [ext] test for em module needed by dronecan

- add empy and setuptools to requirements
- fix dep order for dronecan makefile

* fix type

requirements.txt

@@ -9,6 +9,7 @@ pyqtgraph
 unidecode
 matplotlib
 distro
-empy==3.3.4
+empy
 pexpect
+setuptools
 

sw/ext/Makefile

@@ -34,6 +34,7 @@ include $(PAPARAZZI_SRC)/conf/Makefile.arm-embedded-toolchain
 
 MY_PYTHON := $(shell echo `which python3`)
 MY_MAVLINKTOOLS := $(shell $(MY_PYTHON) -c 'import imp; import future' 2>&1)
+MY_DRONECANTOOLS := $(shell $(MY_PYTHON) -c 'import em' 2>&1)
 
 all: libopencm3 luftboot chibios fatfs libsbp TRICAL hacl-c key_generator rustlink ecl matrix mavlink dronecan
 
@@ -113,7 +114,11 @@ opencv_bebop.build:
 	$(Q)$(MAKE) -C opencv_bebop
 
 dronecan:
+ifneq ($(findstring ModuleNotFoundError, $(MY_DRONECANTOOLS)),ModuleNotFoundError)
 	$(Q)$(MAKE) -C dronecan
+else
+	@echo dronecan not installed, missing package 'em'
+endif
 
 clean:
 	$(Q)if [ -f libopencm3/Makefile ]; then \

sw/ext/dronecan/Makefile

@@ -28,7 +28,7 @@ PAPARAZZI_SRC=../../..
 DRONECAN_DIR=$(PAPARAZZI_SRC)/sw/ext/dronecan
 DSDL_DIR := $(DRONECAN_DIR)/DSDL
 
-all: libcanard DSDL dronecan_dsdlc pydronecan
+all: libcanard DSDL pydronecan dronecan_dsdlc
 
 libcanard: libcanard.sync libcanard.update