PROS make: ***[bin/output.elf] Error 1

Does anyone know how to remedy this error (make: ***[bin/output.elf] Error 1)? We’ve been continually having trouble with this error, and since there is not path listed, we have no idea where the problem actually is. As far as we can tell, there are no syntax errors. Although we have too much code to post all at once, I can post smaller pieces as necessary.

Most likely a problem with the linker, paste all of the output from the build so we can see what else is happening, for example,

**** Build of configuration Default for project testpros ****

make all 
CC -I../include -I../src opcontrol.c
opcontrol.c:54:8: warning: type defaults to 'int' in declaration of 'foo' [enabled by default]
LN ./bin/auto.o ./bin/init.o ./bin/opcontrol.o ./firmware/libccos.a -lgcc -lm to bin/output.elf
./bin/opcontrol.o: In function `operatorControl':
opcontrol.c:(.text.operatorControl+0x8): undefined reference to `foo'
collect2: error: ld returned 1 exit status
make: *** [bin/output.elf] Error 1

**** Build Finished ****

Here I tried to call a function foo() that did not exist.

After looking at the output myself, I may have found the solution. I haven’t been able to upload, but I will update tomorrow. Our team uses an API we custom built, but the API was in a black box folder. After moving the API to the src folder, the problem seems to be fixed, since the errors were coming from undefined methods(which were defined in the API) being called.