undefined reference to Poco::DigestEngine

first, git clone https://github.com/conan-io/examples.git and then cd into libraries/poco/md5 run ./build.sh

got error like that:

+ cmake --build .
Scanning dependencies of target md5
[ 50%] Building CXX object CMakeFiles/md5.dir/md5.cpp.o
[100%] Linking CXX executable bin/md5
CMakeFiles/md5.dir/md5.cpp.o: In function `main':

md5.cpp:(.text.startup+0x9b): undefined reference to `Poco::DigestEngine::digestToHex[abi:cxx11](std::vector<unsigned char, std::allocator<unsigned char> > const&)’ collect2: error: ld returned 1 exit status CMakeFiles/md5.dir/build.make:83: recipe for target ‘bin/md5’ failed make[2]: *** [bin/md5] Error 1 CMakeFiles/Makefile2:72: recipe for target ‘CMakeFiles/md5.dir/all’ failed make[1]: *** [CMakeFiles/md5.dir/all] Error 2 Makefile:83: recipe for target ‘all’ failed make: *** [all] Error 2

[memsharded]

HI @bill-luu

Glad that you fixed it. We will be fixing this for Conan 2.0 (now it will be breaking). To summarize:

• Conan by default uses compiler.libcxx=libstdc++ for wider compatibility in all distros and gcc versions
• If you are running a modern distro and gcc >= 5 you need to change it to libstdc++11
• But if you are running an older distro (even with gcc >= 5) or gcc < 5, then you need to keep the libstdc++

[bill-luu]

I had the same issues as the other two, using Elementary OS 5.0 Juno (Based on Ubuntu 18.04.2)

As suggested, I fixed it by editing ~/.conan/profiles/default and editing the line compilter.libcxx line to compiler.libcxx=libstdc++11

The entire file:

[settings]
os=Linux
os_build=Linux
arch=x86_64
arch_build=x86_64
compiler=gcc
compiler.version=7
compiler.libcxx=libstdc++11
build_type=Release
[options]
[build_requires]
[env]