Makefile error when building Veins project with Omnet++ - c++

Question

I've built a number of projects with Veins on Omnet++ without issues at this stage, and I decided to implement CAM messages into a simulation. However, upon building I arrive at the following error:
12:41:23 **** Incremental Build of configuration release for project v2x ****
make MODE=release all
cd src && make make[1]: Entering directory '/home/veins/workspace.omnetpp/v2x/src'
Creating executable: ../out/clang-release/src/v2x /usr/bin/ld: cannot open output file ../out/clang-release/src/v2x: Is a directory
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[1]:
*** [Makefile:117: ../out/clang-release/src/v2x] Error 1 make[1]: Leaving directory '/home/veins/workspace.omnetpp/v2x/src'
make: *** [Makefile:2: all]
Error 2 "make MODE=release all" terminated with exit code 2.
Build might be incomplete.
12:41:24 Build Failed. 3 errors, 0 warnings. (took 549ms)
My Makefile reads:
#
# OMNeT++/OMNEST Makefile for v2x
#
# This file was generated with the command:
# opp_makemake -f --deep -KINET_PROJ=/home/veins/src/inet -KLTE_PROJ=/home/veins/src/simulte -KVEINS_INET_PROJ=/home/veins/src/veins/subprojects/veins_inet -KVEINS_PROJ=/home/veins/src/veins -DINET_IMPORT -DVEINS_IMPORT -DVEINS_INET_IMPORT -I$$\(INET_PROJ\)/src -I$$\(LTE_PROJ\)/src -I$$\(VEINS_INET_PROJ\)/src -I$$\(VEINS_PROJ\)/src -I. -L$$\(INET_PROJ\)/src -L$$\(LTE_PROJ\)/src -L$$\(VEINS_PROJ\)/src -L$$\(VEINS_INET_PROJ\)/src -lINET$$\(D\) -llte$$\(D\) -lveins$$\(D\) -lveins_inet$$\(D\)
#
# Name of target to be created (-o option)
TARGET_DIR = .
TARGET_NAME = v2x$(D)
TARGET = $(TARGET_NAME)$(EXE_SUFFIX)
TARGET_IMPLIB = $(TARGET_NAME)$(IMPLIB_SUFFIX)
TARGET_IMPDEF = $(TARGET_NAME)$(IMPDEF_SUFFIX)
TARGET_FILES = $(TARGET_DIR)/$(TARGET)
# User interface (uncomment one) (-u option)
USERIF_LIBS = $(ALL_ENV_LIBS) # that is, $(TKENV_LIBS) $(QTENV_LIBS) $(CMDENV_LIBS)
#USERIF_LIBS = $(CMDENV_LIBS)
#USERIF_LIBS = $(TKENV_LIBS)
#USERIF_LIBS = $(QTENV_LIBS)
# C++ include paths (with -I)
INCLUDE_PATH = -I$(INET_PROJ)/src -I$(LTE_PROJ)/src -I$(VEINS_INET_PROJ)/src -I$(VEINS_PROJ)/src -I.
# Additional object and library files to link with
EXTRA_OBJS =
# Additional libraries (-L, -l options)
LIBS = $(LDFLAG_LIBPATH)$(INET_PROJ)/src $(LDFLAG_LIBPATH)$(LTE_PROJ)/src $(LDFLAG_LIBPATH)$(VEINS_PROJ)/src $(LDFLAG_LIBPATH)$(VEINS_INET_PROJ)/src -lINET$(D) -llte$(D) -lveins$(D) -lveins_inet$(D)
# Output directory
PROJECT_OUTPUT_DIR = ../out
PROJECTRELATIVE_PATH = src
O = $(PROJECT_OUTPUT_DIR)/$(CONFIGNAME)/$(PROJECTRELATIVE_PATH)
# Object files for local .cc, .msg and .sm files
OBJS = \
$O/v2x/GeneralMessageSerializer.o \
$O/v2x/VeinsInetApplicationBase.o \
$O/v2x/VeinsInetManager.o \
$O/v2x/VeinsInetManagerBase.o \
$O/v2x/VeinsInetManagerForker.o \
$O/v2x/VeinsInetMobility.o \
$O/v2x/VeinsInetSampleApplication.o \
$O/v2x/VeinsInetSampleMessageSerializer.o \
$O/v2x/GeneralMessage_m.o \
$O/v2x/VeinsInetSampleMessage_m.o
# Message files
MSGFILES = \
v2x/GeneralMessage.msg \
v2x/VeinsInetSampleMessage.msg
# SM files
SMFILES =
# Other makefile variables (-K)
INET_PROJ=/home/veins/src/inet
LTE_PROJ=/home/veins/src/simulte
VEINS_INET_PROJ=/home/veins/src/veins/subprojects/veins_inet
VEINS_PROJ=/home/veins/src/veins
#------------------------------------------------------------------------------
# Pull in OMNeT++ configuration (Makefile.inc)
ifneq ("$(OMNETPP_CONFIGFILE)","")
CONFIGFILE = $(OMNETPP_CONFIGFILE)
else
CONFIGFILE = $(shell opp_configfilepath)
endif
ifeq ("$(wildcard $(CONFIGFILE))","")
$(error Config file '$(CONFIGFILE)' does not exist -- add the OMNeT++ bin directory to the path so that opp_configfilepath can be found, or set the OMNETPP_CONFIGFILE variable to point to Makefile.inc)
endif
include $(CONFIGFILE)
# Simulation kernel and user interface libraries
OMNETPP_LIBS = $(OPPMAIN_LIB) $(USERIF_LIBS) $(KERNEL_LIBS) $(SYS_LIBS)
ifneq ($(PLATFORM),win32.x86_64)
LIBS += -Wl,-rpath,$(abspath $(INET_PROJ)/src) -Wl,-rpath,$(abspath $(LTE_PROJ)/src) -Wl,-rpath,$(abspath $(VEINS_PROJ)/src) -Wl,-rpath,$(abspath $(VEINS_INET_PROJ)/src)
endif
COPTS = $(CFLAGS) $(IMPORT_DEFINES) -DINET_IMPORT -DVEINS_IMPORT -DVEINS_INET_IMPORT $(INCLUDE_PATH) -I$(OMNETPP_INCL_DIR)
MSGCOPTS = $(INCLUDE_PATH)
SMCOPTS =
# we want to recompile everything if COPTS changes,
# so we store COPTS into $COPTS_FILE (if COPTS has changed since last build)
# and make the object files depend on it
COPTS_FILE = $O/.last-copts
ifneq ("$(COPTS)","$(shell cat $(COPTS_FILE) 2>/dev/null || echo '')")
$(shell $(MKPATH) "$O")
$(file >$(COPTS_FILE),$(COPTS))
endif
#------------------------------------------------------------------------------
# User-supplied makefile fragment(s)
-include makefrag
#------------------------------------------------------------------------------
# Main target
all: $(TARGET_FILES)
$(TARGET_DIR)/% :: $O/%
#mkdir -p $(TARGET_DIR)
$(Q)$(LN) $< $#
ifeq ($(TOOLCHAIN_NAME),clang-msabi)
-$(Q)-$(LN) $(<:%.dll=%.lib) $(#:%.dll=%.lib) 2>/dev/null
endif
$O/$(TARGET): $(OBJS) $(wildcard $(EXTRA_OBJS)) Makefile $(CONFIGFILE)
#$(MKPATH) $O
#echo Creating executable: $#
$(Q)$(CXX) $(LDFLAGS) -o $O/$(TARGET) $(OBJS) $(EXTRA_OBJS) $(AS_NEEDED_OFF) $(WHOLE_ARCHIVE_ON) $(LIBS) $(WHOLE_ARCHIVE_OFF) $(OMNETPP_LIBS)
.PHONY: all clean cleanall depend msgheaders smheaders
.SUFFIXES: .cc
$O/%.o: %.cc $(COPTS_FILE) | msgheaders smheaders
#$(MKPATH) $(dir $#)
$(qecho) "$<"
$(Q)$(CXX) -c $(CXXFLAGS) $(COPTS) -o $# $<
%_m.cc %_m.h: %.msg
$(qecho) MSGC: $<
$(Q)$(MSGC) -s _m.cc -MD -MP -MF $O/$(basename $<)_m.h.d $(MSGCOPTS) $?
%_sm.cc %_sm.h: %.sm
$(qecho) SMC: $<
$(Q)$(SMC) -c++ -suffix cc $(SMCOPTS) $?
msgheaders: $(MSGFILES:.msg=_m.h)
smheaders: $(SMFILES:.sm=_sm.h)
clean:
$(qecho) Cleaning $(TARGET)
$(Q)-rm -rf $O
$(Q)-rm -f $(TARGET_FILES)
$(Q)-rm -f $(call opp_rwildcard, . , *_m.cc *_m.h *_sm.cc *_sm.h)
cleanall:
$(Q)$(CLEANALL_COMMAND)
$(Q)-rm -rf $(PROJECT_OUTPUT_DIR)
help:
#echo "$$HELP_SYNOPSYS"
#echo "$$HELP_TARGETS"
#echo "$$HELP_VARIABLES"
#echo "$$HELP_EXAMPLES"
# include all dependencies
-include $(OBJS:%=%.d) $(MSGFILES:%.msg=$O/%_m.h.d)
It's correct in saying that clang-release/src/v2x is a directory, but it has always been so (even before making the recent changes) and it hasn't produced this error.
Other than the MakeFile error, there is no other error in any of the scripts for the project.

Answer 1

You want to create the executable file clang-release/src/v2x but you can't because that file already exists and is a directory.
The name of the file you attempt to create is
v2x$(D)$(EXE_SUFFIX) and nowhere in your Makefile do you have Make variables D or EXE_SUFFIX defined, so they evaluate to empty strings.
Probably you want to make sure you have D and EXE_SUFFIX defined somewhere.
There is a $(CONFIGFILE) you are including, Make finds it but you did not provide the text of it, check if these variables should be defined in there but are not.