Not finding lib.rs.cc on macos when running cmake build

[stexa]

Thanks for your project!
I get the following issue when running cmake --build . on macos:

clang: error: no such file or directory: '/Users/{USER}/cpp-with-rust/target/cxxbridge/blobstore/src/lib.rs.cc'
clang: error: no input files
make[2]: *** [CMakeFiles/cpp_with_rust.dir/target/cxxbridge/blobstore/src/lib.rs.cc.o] Error 1
make[1]: *** [CMakeFiles/cpp_with_rust.dir/all] Error 2
make: *** [all] Error 2

[stexa]

It is working now:
I had to manually run cargo build --release before.
Even running cargo build was not generating the lib.rs.cc file.
Do you know why it is not being built by cmake?

[pedrolcl]

I've found this issue as well when working on this project in Linux, so it is not a macos only thing.

It can be triggered by the cmake clean target after a successful build. Any other build attempt after that will trigger the reported error. It doesn't matter if the build tool is GNU Make or Ninja. For instance:

cd cpp-with-rust
cmake -S . -B build
# (configuration succeeds)
cmake --build build/
# (build succeeds)
cmake --build build/ --target clean
# (clean removes two files)
cmake --build build/
# (build fails!)

Another available workaround is running cargo clean before building.

The problem is that the cmake clean target removes the OUTPUT files generated by add_custom_command(), but cargo doesn't know how to regenerate them when the target directory is already populated by the last cargo execution.

See my proposed solution on the next pull request.