Compile transitive dependency issues

[FlyingCat2023]

Hi all,
First of all, I created a shared library lib_A, linking to Ginkgo. In library lib_A, I have a class in which func_a using following codes to generate a Csr-type matrix.
auto A = gko::share(mtx::create(exec));
A.get()->read(matrix_assembly_data);
There is no issue when i compile all codes and add them to lib_A.
Secondly, I created another shared libary lib_B. Libray lib_B is linked to lib_A. In somewhere Lib_B calls the func_a in lib_A. Then compilation failed to generate the lib_B, Error as below.

/usr/bin/ld: CMakeFiles/test_ginkgo.dir/test_ginkgo.cpp.o:(.data.rel.ro._ZTVN3gko6matrix3CsrIdmEE[_ZTVN3gko6matrix3CsrIdmEE]+0x80): undefined reference to `gko::matrix::Csr<double, unsigned long>::apply_impl(gko::LinOp const*, gko::LinOp const*, gko::LinOp const*, gko::LinOp*) const'

[upsj]

You are trying to use an unsigned IndexType, Ginkgo only supports signed index types

[upsj]

I opened an issue #1555 to make such errors visible before the linking stage

[FlyingCat2023]

Hi Upsj,

Many thanks for the prompt reply.
Indeed, the compilation error comes from the un-supported IndexType. Changing it back to singed type index solves this issue.