Hi,
I’m creating a derivation for qiskit-aer, a quantum computer simulator.
qiskit-aer is written in C++ and compiled using CMake.
Also, it has a Cython wrapper for using it from Python.
Since this module requires to be linked against Python, I used NIX_CFLAGS_COMPILE and NIX_LDFLAGS as follows:
{ stdenv
, isPy3k
, buildPythonPackage
, fetchFromGitHub
, cmake
, blas
, liblapack
, scikit-build
, cython
, python
}:
buildPythonPackage rec {
pname = "qiskit-aer";
version = "0.1.1";
disabled = !isPy3k;
src = fetchFromGitHub {
owner = "Qiskit";
repo = "qiskit-aer";
rev = "21fdd7e7503dc8ac7dfaee24b927f26d1eff42f8";
sha256 = "1p4w1jg6sl9xvmp98nrn5s6drp1rcl67vzi5xdh639kf498y49nz";
};
buildInputs = [
scikit-build
cython
cmake
blas
liblapack
];
NIX_CFLAGS_COMPILE = [
"-I${python.outPath}/include/${python.executable}"
];
NIX_LDFLAGS = [
"-L${python.outPath}/lib"
];
}
I can compile the sources, but link fails because Python library is missing.
The error message is:
[ 45%] Linking CXX shared module statevector_controller_wrapper.cpython-37m-x86_64-linux-gnu.so
/nix/store/3xwc1ip20b0p68sxqbjjll0va4pv5hbv-binutils-2.30/bin/ld: cannot find -lpython3.7m
collect2: error: ld returned 1 exit status
although I have libpython3.7m.so in the directory I specified:
[pan@pan-nixos:~/nixpkgs]$ ls /nix/store/6lm4gi5iv8fbf1b1mm6g3gfnnv63f1gn-python3-3.7.1/lib/
libpython3.7m.so libpython3.7m.so.1.0 libpython3.so pkgconfig python3.7
How to build a package that link against Python?
If you want to test the code, you can fetch the following branch (qiskit-0.7.1):
Since qiskit-aer uses scikit-build for invoking cmake during the setup, I included scikit-build.