lwm2m_client sample fails with "Compiling the C compiler identification source file "CMakeCCompilerId.c" failed."

[pascal_dao]

Hello, 

I am trying to build the lwm2m_client sample on my ubuntu 16.04 machine.  I tried building for nrf9160_pca10090ns and nrf9160_pca20035ns The build fails with:

ninja: build stopped: subcommand failed.
ERROR: command exited with status 1: /usr/local/bin/cmake --build /home/pascal/nrf/samples/nrf9160/lwm2m_client/build

When I look at the CMakeError.log file this is what it says:

Compiling the C compiler identification source file "CMakeCCompilerId.c" failed.
Compiler: /opt/gnuarmemb/gcc-arm-none-eabi-8-2019-q3-update/bin/arm-none-eabi-gcc 
Build flags: 
Id flags:  

The output was:
1
/opt/gnuarmemb/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /opt/gnuarmemb/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/lib/libc.a(lib_a-exit.o): in function `exit':
exit.c:(.text.exit+0x2c): undefined reference to `_exit'
collect2: error: ld returned 1 exit status


Compiling the CXX compiler identification source file "CMakeCXXCompilerId.cpp" failed.
Compiler: /opt/gnuarmemb/gcc-arm-none-eabi-8-2019-q3-update/bin/arm-none-eabi-g++ 
Build flags: 
Id flags:  

The output was:
1
/opt/gnuarmemb/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /opt/gnuarmemb/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/lib/libc.a(lib_a-exit.o): in function `exit':
exit.c:(.text.exit+0x2c): undefined reference to `_exit'
collect2: error: ld returned 1 exit status

I should mention that I only run into this error with this one particular sample, I have successfully built applications with this compiler before.

I am not sure what this due to. I tried using a more recent compiler. I installed gcc-arm-none-eabi-9-2019-q4-major and edited my env variables accordingly but I get the same error with the new compiler as well.

Regards,

[Heidi-Irene Harvey Sollie]

Hi!

Did you remember to set CONFIG_APP_LWM2M_SERVER?

Best regards,

Heidi

[pascal_dao]

Yes, I did. I could not find the IP address of the Leshan Demo Server anywhere so I pinged https://leshan.eclipseprojects.io/ and got back 23.97.187.154. Is that the correct one?

[Heidi-Irene Harvey Sollie]

I'm not sure but you should still be able to build. Are you remembering quotation marks around the address?

CONFIG_APP_LWM2M_SERVER="23.97.187.154"

[pascal_dao]

Yes, this is the line from my prj.conf

[Heidi-Irene Harvey Sollie]

Which NCS tag are you on?

[pascal_dao]

I am on the master branch. This one https://github.com/NordicPlayground/fw-nrfconnect-nrf. But I actually don't have a ncs folder. As in I am not working from /ncs/nrf. From root I only have /nrf and directly work from there. Do you think that could be issue? Do I need to put nrf inside ncs?

[Heidi-Irene Harvey Sollie]

Hi, that depends. Do you still have all the other directories that belong to ncs, like zephyr, modules, mcuboot etc.?

If not, then yes that is definitely the problem. 

[pascal_dao]

No, I don't have those. Below is what my /nrf folder looks like. Okay I will put this /nrf in /ncs with all the other directories and see if that fixes it.

[pascal_dao]

Hello Heidi, 

So I took your advice. I removed the existing west installation and re-went through step 2 of the nRF connect Getting started Assisstant. I now have a ncs folder and folders such as modules, zephyr, etc.. However, the problem persists. Furthermore, the mcuboot folder was not installed in ncs when I ran west update and I got an error when I ran 

pip3 install --user -r mcuboot/scripts/requirements.txt

mcuboot might be the culprit. Do you now where I find the folder and download it on my machine?

Regards,

[pascal_dao]

Hello Heidi,

So I found the mcuboot folder in an older installation on my windows machine. I copied it to the ncs folder and ran west update. Now the sample builds fine for nrf9160_pca10090ns, but when I try to build it for nrf9160_20035ns (My actual target hardware). I get these errors:

../src/lwm2m/lwm2m_button.c: In function 'handle_button_events':
../src/lwm2m/lwm2m_button.c:32:23: error: operator '>' has no left operand
 #if CONFIG_FLIP_INPUT > 0
                       ^
../src/lwm2m/lwm2m_button.c: In function 'lwm2m_init_button':
../src/lwm2m/lwm2m_button.c:65:23: error: operator '!=' has no left operand
 #if CONFIG_FLIP_INPUT != UI_BUTTON_1
                       ^~
../src/lwm2m/lwm2m_button.c:76:23: error: operator '!=' has no left operand
 #if CONFIG_FLIP_INPUT != UI_BUTTON_2
                       ^~
../src/lwm2m/lwm2m_button.c:87:23: error: operator '!=' has no left operand
 #if CONFIG_FLIP_INPUT != UI_SWITCH_1
                       ^~
../src/lwm2m/lwm2m_button.c:98:23: error: operator '!=' has no left operand
 #if CONFIG_FLIP_INPUT != UI_SWITCH_2
                       ^~
At top level:
../src/lwm2m/lwm2m_button.c:20:14: warning: 'timestamp' defined but not used [-Wunused-variable]
 static s32_t timestamp[4];

Are there some configs I need to set or is this sample not compatible with that board. 

Regards,

[Heidi-Irene Harvey Sollie]

Hi, 

Unfortunately, the LwM2M Client sample has not been written for the pca20035 board. In theory, the sample should work on the board, so you could try to port it yourself.