Error building examples on Linux

[willidu]

I am working on a larger project that use SUNDIALS and want to test its functionality independently. I have tried to build the CXX examples. Most of them work, but some of them do not.

Current Behavior:

Building CVODE CXX examples fail due to undefined references.

Steps To Reproduce:

Fork/clone the repo, checkout v7.0.0. Occurs on master as well
Build SUNDIALS with CMake:

#!/bin/bash
# SUNDIALS
mkdir -p build
mkdir -p install
cd build

cmake_flags="-DCMAKE_INSTALL_PREFIX=../install \
             -DBUILD_STATIC_LIBS=ON \
             -DBUILD_SHARED_LIBS=OFF \
             -DEXAMPLES_INSTALL=ON
             -DEXAMPLES_INSTALL_PATH=../install/examples \
             -DEXAMPLES_ENABLE_CXX=ON"
if [[ "$(uname)" == "Linux" ]]; then
    cmake_flags="$cmake_flags -DCMAKE_C_FLAGS=-fPIC"
fi

cmake $cmake_flags ..
make config=release -j$(nproc)
make install
cd ..
echo "SUNDIALS built."

Build some examples

cd install/examples/nvector/serial
make
./test_nvector_serial 10 0

Output is success.

cd install/examples/cvode/CXX_serial
make

Output (see full output.txt):

~/Git/sundials/install/examples/cvode/CXX_serial$ make
/usr/bin/c++ -o cv_heat2D cv_heat2D.o -O3 -DNDEBUG -std=c++14  -I/home/wdugan/Git/sundials/install/include -I. -L/home/wdugan/Git/sundials/install/lib -lsundials_cvode -lsundials_nvecserial -lm -Wl,-rpath,/home/wdugan/Git/sundials/install/lib
/usr/bin/ld: cv_heat2D.o: in function `PSolve(double, _generic_N_Vector*, _generic_N_Vector*, _generic_N_Vector*, _generic_N_Vector*, double, double, int, void*)':
cv_heat2D.cpp:(.text+0x13): undefined reference to `N_VProd'
/usr/bin/ld: cv_heat2D.o: in function `PSetup(double, _generic_N_Vector*, _generic_N_Vector*, int, int*, double, void*)':
cv_heat2D.cpp:(.text+0x4b6): undefined reference to `N_VGetArrayPointer'
/usr/bin/ld: cv_heat2D.cpp:(.text+0x57e): undefined reference to `N_VConst'
/usr/bin/ld: cv_heat2D.o: in function `Solution(double, _generic_N_Vector*, UserData&)':
cv_heat2D.cpp:(.text+0x624): undefined reference to `N_VGetArrayPointer'

...

collect2: error: ld returned 1 exit status
make: *** [Makefile:85: examples] Error 1

Environment:

• SUNDIALS v7.0.0
• Ubuntu 24.04 LTS
• GCC 13.2.0

Edit - Test outputs

As the documentation suggests, i have run 'make test' and 'make test_install'. All is success.
test_output.txt

[willidu]

The problem has been identified. The Makefile generated for the examples during the SUNDIALS build does not account for which third-party libraries are enabled etc. The file includes

all: examples examples_bl examples_klu examples_slumt

Since LAPACK was disabled when building SUNDIALS the examples_bl should not be built. This also explains why running CMake to regenereate the Makefile fixes the issue.

Suggested fix

Update the docs to make this more clear (coming from a non-native English speaker).

[balos1]

Thanks @willidu. We will try and make the documentation more clear about when re-running CMake is necessary.

[Steven-Roberts]

I noticed when running

cd install/examples/cvode/CXX_serial
make VERBOSE=1

some linking flags appear to be missing for cv_heat2D.cpp and cv_kpr.cpp:

/usr/bin/c++ -O3 -DNDEBUG -O3 -DNDEBUG -std=c++14 -I/home/roberts115/Documents/SUNDIALS/SUNDIALS/main/install/include -I. -c cv_heat2D.cpp                                                                           
/usr/bin/c++ -O3 -DNDEBUG -O3 -DNDEBUG -std=c++14 -I/home/roberts115/Documents/SUNDIALS/SUNDIALS/main/install/include -I. -c cv_kpr.cpp                                                                              
/usr/bin/c++ -o cv_heat2D cv_heat2D.o -O3 -DNDEBUG -std=c++14  -I/home/roberts115/Documents/SUNDIALS/SUNDIALS/main/install/include -I. -L/home/roberts115/Documents/SUNDIALS/SUNDIALS/main/install/lib64 -lsundials_c
vode -lsundials_nvecserial -lm -Wl,-rpath,/home/roberts115/Documents/SUNDIALS/SUNDIALS/main/install/lib64

[balos1]

@Steven-Roberts I think core is missing from here.