Esp-idf: smart_config build fail (IDFGH-3715)

[iloop2020]

Introduction

My project(esp32-idf v4.0.1) need the smart_config and some external component, then I base on smart_config example.
When if try to enable some external component by updating the "smart_config/main/CMakeLists.txt",
idf.py build show a lot of mbedtls error message as below:
esp-idf/wpa_supplicant/libwpa_supplicant.a(crypto_mbedtls.c.obj):(.literal.ecp_opp+0x0): undefined reference to `mbedtls_ecp_copy'
it seems when REQUIRES is added, the original linker is changed then make mbedtls not linked ?

Updated smart_config/main/CMakeLists.txt

idf_component_register(SRCS "smartconfig_main.c"    
                    INCLUDE_DIRS "."    
                    REQUIRES nvs_flash wpa_supplicant)    

Original smart_config/main/CMakeLists.txt

idf_component_register(SRCS "smartconfig_main.c"
                    INCLUDE_DIRS ".")

Thank you.

[liuzfesp]

Hi @iloop2020 everything looks OK on my side, suggest:

• idf.py clean
• git submodule update -f
• make the original smart_config example pass build
• modify the CMakeLists.txt and make the build pass

[iloop2020]

Hi @liuzfesp ,

Thank you for your support.

Actually, I did the same procedures, but still fail,
Are you using esp32-idf v4.0.1 ?

Thank you.

[liuzfesp]

Yes, it's IDF tagged v4.0.1: 4c81978, no other modifications except the CMakeLists.txt.

[tobymurray]

I can reproduce iloop2020's failing example with release/4.0 on 48ea44f on Ubuntu 18.04, but when I go back to 4c81978 it also fails. If it's something environmental, it seems like it's gone wrong in both our environments.

Specifically:

• idf.py clean
• git submodule update -f
• idf.py build in examples/wifi-/smart_config
• succeeds on both 48ea44f and 4c81978

Specifically:

• idf.py clean
• git submodule update -f
• update smart_config/main/CMakeLists.txt to include the requires mentioned above
• idf.py build in examples/wifi-/smart_config
• fails on both 48ea44f and 4c81978

...
/home/me/.espressif/tools/xtensa-esp32-elf/esp-2019r2-8.2.0/xtensa-esp32-elf/bin/../lib/gcc/xtensa-esp32-elf/8.2.0/../../../../xtensa-esp32-elf/bin/ld: esp-idf/wpa_supplicant/libwpa_supplicant.a(crypto_mbedtls.c.obj):(.literal.ecp_opp+0x0): undefined reference to `mbedtls_ecp_copy'
/home/me/.espressif/tools/xtensa-esp32-elf/esp-2019r2-8.2.0/xtensa-esp32-elf/bin/../lib/gcc/xtensa-esp32-elf/8.2.0/../../../../xtensa-esp32-elf/bin/ld: esp-idf/wpa_supplicant/libwpa_supplicant.a(crypto_mbedtls.c.obj):(.literal.ecp_opp+0x4): undefined reference to `mbedtls_mpi_cmp_int'
/home/me/.espressif/tools/xtensa-esp32-elf/esp-2019r2-8.2.0/xtensa-esp32-elf/bin/../lib/gcc/xtensa-esp32-elf/8.2.0/../../../../xtensa-esp32-elf/bin/ld: esp-idf/wpa_supplicant/libwpa_supplicant.a(crypto_mbedtls.c.obj):(.literal.ecp_opp+0x8): undefined reference to `mbedtls_mpi_sub_mpi'
/home/me/.espressif/tools/xtensa-esp32-elf/esp-2019r2-8.2.0/xtensa-esp32-elf/bin/../lib/gcc/xtensa-esp32-elf/8.2.0/../../../../xtensa-esp32-elf/bin/ld: esp-idf/wpa_supplicant/libwpa_supplicant.a(crypto_mbedtls.c.obj):(.literal.crypto_bignum_init+0x0): undefined reference to `mbedtls_mpi_init'\
...

Trying this on a Windows 10 machine, with 4.0.1 (commit 48ea44f and 7abb8e7) I was able to build successfully in both cases. @iloop2020 - what OS are you on?

[iloop2020]

Hi @tobymurray ,

I am using Ubuntu mate 18.04 also.

[liuzfesp]

Hello, could you try following way:

• Start a new terminal
• cd $IDF_PATH
• install.sh
• source export.sh

then rebuild the example.

[tobymurray]

I pulled release/4.0 (now on 7abb8e7) and did as you described with no difference in the result, full output is here: https://gist.github.com/tobymurray/e357bf8f8fa4a2e14361915d7869c567

[BrianPugh]

just weighing in, I'm experiencing similar mbedtls linking issues from wpa_supplicant using a super clean v4.0.1 esp-idf install. I'm also on Ubuntu. See details at https://github.com/BrianPugh/cookiecutter-esp32-webserver/issues/2

[tobymurray]

I just tried the just-announced 4.1 RC - I successfully built in the scenario described above (i.e. I was unable to reproduce this issue on the 4.1 RC). Poking through the resolved issues, #5321 looks vaguely similar - related at all?

[sagb2015]

@iloop2020 Can you provide the sdkconfig? We are not able to reproduce the issue.

[BrianPugh]

what's not reproduceable about this? I get this on v4.0.1 on a clean install, default everything (running Ubuntu 19.04)

[tobymurray]

Same here except on Ubuntu 18.04. There is no customization required beyond what's mentioned in the original post. To be explicit about it:

• install the ESP-IDF with version 4.0.1
• add REQUIRES nvs_flash wpa_supplicant to esp-idf/examples/wifi/smart_config/main/CMakeLists.txt
• idf.py build that project

@sagb2015 or @Alvin1Zhang - are you saying you have tried this on Ubuntu and it works fine there, or you're unable to reproduce this on another OS? As I noted above, this looks like a platform dependent problem to me. Using exactly the same steps I was successfully able to build on Windows but was not on Ubuntu 18.04.

[projectgus]

Hi all,

Thanks for being patient while we looked into this.

We were indeed unable to reproduce this on three different developer systems (a mixture of Ubuntu and MacOS) with ESP-IDF v4.0.1. I just now set up a clean VM install of Ubuntu Desktop 18.04.3 and ESP-IDF v4.0.1 and could reproduce it there.

The wpa_supplicant component & mbedtls component libraries have a dependency cycle, via some other component libraries. It seems like CMake can resolve this set of relationships in some situations and not in others - it may be CMake version related (I can't reproduce on CMake 16, Ubuntu 18.04 has CMake 10.2), or it might be some other implementation-specific factor.

A quick fix in ESP-IDF is to add the following line to the very end of components/wpa_supplicant/CMakeLists.txt:

    set_property(TARGET ${COMPONENT_LIB} APPEND PROPERTY LINK_INTERFACE_MULTIPLICITY 3)

(This may also be how we fix it permanently, or we may fix it by cleaning up the dependency cycle.)