follow the tutorial do a little test, undefined reference,why? about cxx

[dtolnay]

src/build.rs is the wrong location for a Cargo build script. It needs to be build.rs in the same directory that contains Cargo.toml. Or else you need to put build = "src/build.rs" into the Cargo.toml.

[aohan237]

thanks

[aohan237]

@dtolnay from doc https://docs.rs/cxx-build/1.0.98/cxx_build/static.CFG.html#cfginclude_prefix
`The prefix at which C++ code from your crate as well as directly dependent crates can access the code generated during this build.

By default, the include_prefix is equal to the name of the current crate. That means if your crate is called demo and has Rust source files in a src/ directory and maybe some handwritten C++ header files in an include/ directory, then the current crate as well as downstream crates might include them as follows:

// include one of the handwritten headers:
#include "demo/include/wow.h"

// include a header generated from Rust cxx::bridge:
#include "demo/src/lib.rs.h"

By modifying CFG.include_prefix we can substitute a prefix that is different from the crate name if desired. Here we’ll change it to "path/to" which will make import paths take the form "path/to/include/wow.h" and "path/to/src/lib.rs.h".`

what is the path/to means? it is not a absolute path. i tried.
so. the path/to means the same path as the build.rs located in ?

what is i have a cpp in src like detect as above, but it includes an opencv4 for example, like located in dir :
src/lib/opencv4
and other lib like
src/lib/thirdparty

how to include these libs? the tutorial has no example on this

i tried several ways, it shows that .h has no that file or dirs