`Libra` error: missing shared library `libpipy.so`

[MrBeanCpp]

I used the following command to compile Libra into a binary:

cargo build --release --bin libra

The compilation process was OK, but when I ran libra command, I got an error:

libra: error while loading shared libraries: libpipy.so: cannot open shared object file: No such file or directory

However, if I run libra directly via cargo run, there are no problem at all.
And this issue occurred after libra introduced gemini for p2p download.

[Hou-Xiaoxuan]

That is because Cargo doesn’t propagate the crate’s link arguments to higher-level crates. In Neptune’s build.rs, we set two arguments: rpath and link-search. The rpath is intended for the final binary to link to the library, and link-search allows Cargo to locate the library.

    println!(
        "cargo:rustc-link-arg=-Wl,-rpath,{}/build,-rpath,{}",
        dst.display(),
        origin_path
    );
    println!("cargo:rustc-link-search={}/build", dst.display());

The problem is that link-search can be passed to crates that use Neptune, but rpath cannot, as noted in this Cargo issue. So, you can use cargo run to execute the program, but you can’t run Libra directly.

One way to address this is to add these arguments to any binaries's build.rs that use Neptune, either directly or indirectly, as demonstrated in this commit. Additionally, you would need to copy libpipy.so to the directory where the executable is located.