My project uses zlib:
println!("cargo:rustc-link-lib=static=zlib");
which was working but now gives:
error: could not find native static library zlib, perhaps an -L flag is missing?
ldconfig -p | grep libz
libz3.so.4 (libc6,x86-64) => /lib/x86_64-linux-gnu/libz3.so.4
libz3.so (libc6,x86-64) => /lib/x86_64-linux-gnu/libz3.so
libzstd.so.1 (libc6,x86-64) => /lib/x86_64-linux-gnu/libzstd.so.1
libz.so.1 (libc6,x86-64) => /lib/x86_64-linux-gnu/libz.so.1
libz.so.1 (libc6) => /lib32/libz.so.1
libz.so (libc6,x86-64) => /lib/x86_64-linux-gnu/libz.so
If I change to dynamic:
println!("cargo:rustc-link-lib=zlib");
I get lots of undefined reference errors related to zlib:
zmbv.c:(.text.unlikely+0x16): undefined reference to inflateEnd'`
also tried
println!("cargo:rustc-link-lib=dylib=z");
println!("cargo:rustc-link-lib=z");
println!("cargo:rustc-link-lib=static=z");
adding
println!("cargo:rustc-link-search=/usr/lib/x86_64-linux-gnu/");
println!("cargo:rustc-link-lib=static=z");
makes the 'zlib not found' (on static mode) error go away but I still get the same undefined references
The error is coming from within zmbv.c which is part of libavcodec. Whichever crate is linking libavcodec should also be responsible for linking all of its dependencies.
Your previous topic mentioned using the ffmeg-sys-next crate. This crate will automatically find and link all the necessary libraries by default, using pkg-config. You shouldn't need your own build script.
For example, just by adding this dependency and calling an avformat function, my test program gets linked to all of these libraries, without a build script:
$ cat Cargo.toml
[package]
name = "ff"
version = "0.1.0"
edition = "2018"
[dependencies]
ffmpeg-sys-next = "4"
$ cat src/main.rs
fn main() {
unsafe { ffmpeg_sys_next::avformat_flush(0 as _); }
}
$ cargo build
Finished dev [unoptimized + debuginfo] target(s) in 0.09s
$ ldd ./target/debug/ff
linux-vdso.so.1 (0x00007ffd183ff000)
libavformat.so.58 => /usr/lib/x86_64-linux-gnu/libavformat.so.58 (0x00007f58558f1000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f58558eb000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f58558c8000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f58558ad000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f58556bb000)
/lib64/ld-linux-x86-64.so.2 (0x00007f5855bbc000)
libavcodec.so.58 => /usr/lib/x86_64-linux-gnu/libavcodec.so.58 (0x00007f58540fe000)
libavutil.so.56 => /usr/lib/x86_64-linux-gnu/libavutil.so.56 (0x00007f5853fd3000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f5853e84000)
libxml2.so.2 => /usr/lib/x86_64-linux-gnu/libxml2.so.2 (0x00007f5853cca000)
libbz2.so.1.0 => /lib/x86_64-linux-gnu/libbz2.so.1.0 (0x00007f5853cb7000)
libgme.so.0 => /usr/lib/x86_64-linux-gnu/libgme.so.0 (0x00007f5853c6a000)
libopenmpt.so.0 => /usr/lib/x86_64-linux-gnu/libopenmpt.so.0 (0x00007f5853a7d000)
libchromaprint.so.1 => /usr/lib/x86_64-linux-gnu/libchromaprint.so.1 (0x00007f5853a65000)
libbluray.so.2 => /usr/lib/x86_64-linux-gnu/libbluray.so.2 (0x00007f5853a14000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f58539f8000)
libgnutls.so.30 => /usr/lib/x86_64-linux-gnu/libgnutls.so.30 (0x00007f5853822000)
libssh-gcrypt.so.4 => /usr/lib/x86_64-linux-gnu/libssh-gcrypt.so.4 (0x00007f5853796000)
libswresample.so.3 => /usr/lib/x86_64-linux-gnu/libswresample.so.3 (0x00007f5853772000)
libvpx.so.6 => /usr/lib/x86_64-linux-gnu/libvpx.so.6 (0x00007f585353a000)
libwebpmux.so.3 => /usr/lib/x86_64-linux-gnu/libwebpmux.so.3 (0x00007f5853330000)
libwebp.so.6 => /usr/lib/x86_64-linux-gnu/libwebp.so.6 (0x00007f58530c7000)
liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007f585309e000)
librsvg-2.so.2 => /usr/lib/x86_64-linux-gnu/librsvg-2.so.2 (0x00007f58527ae000)
libgobject-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 (0x00007f585274e000)
libglib-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f5852623000)
libcairo.so.2 => /usr/lib/x86_64-linux-gnu/libcairo.so.2 (0x00007f5852500000)
libzvbi.so.0 => /usr/lib/x86_64-linux-gnu/libzvbi.so.0 (0x00007f5852471000)
libsnappy.so.1 => /usr/lib/x86_64-linux-gnu/libsnappy.so.1 (0x00007f5852466000)
libaom.so.0 => /usr/lib/x86_64-linux-gnu/libaom.so.0 (0x00007f5851fc8000)
libcodec2.so.0.9 => /usr/lib/x86_64-linux-gnu/libcodec2.so.0.9 (0x00007f58511e4000)
libgsm.so.1 => /usr/lib/x86_64-linux-gnu/libgsm.so.1 (0x00007f58511d3000)
libmp3lame.so.0 => /usr/lib/x86_64-linux-gnu/libmp3lame.so.0 (0x00007f585115b000)
libopenjp2.so.7 => /usr/lib/x86_64-linux-gnu/libopenjp2.so.7 (0x00007f5851105000)
libopus.so.0 => /usr/lib/x86_64-linux-gnu/libopus.so.0 (0x00007f58510a6000)
libshine.so.3 => /usr/lib/x86_64-linux-gnu/libshine.so.3 (0x00007f5850e9b000)
libspeex.so.1 => /usr/lib/x86_64-linux-gnu/libspeex.so.1 (0x00007f5850e7d000)
libtheoraenc.so.1 => /usr/lib/x86_64-linux-gnu/libtheoraenc.so.1 (0x00007f5850e3e000)
libtheoradec.so.1 => /usr/lib/x86_64-linux-gnu/libtheoradec.so.1 (0x00007f5850e1e000)
libtwolame.so.0 => /usr/lib/x86_64-linux-gnu/libtwolame.so.0 (0x00007f5850df8000)
libvorbis.so.0 => /usr/lib/x86_64-linux-gnu/libvorbis.so.0 (0x00007f5850dca000)
libvorbisenc.so.2 => /usr/lib/x86_64-linux-gnu/libvorbisenc.so.2 (0x00007f5850d1f000)
libwavpack.so.1 => /usr/lib/x86_64-linux-gnu/libwavpack.so.1 (0x00007f5850cf3000)
libx264.so.155 => /usr/lib/x86_64-linux-gnu/libx264.so.155 (0x00007f5850a33000)
libx265.so.179 => /usr/lib/x86_64-linux-gnu/libx265.so.179 (0x00007f584fac5000)
libxvidcore.so.4 => /usr/lib/x86_64-linux-gnu/libxvidcore.so.4 (0x00007f584f9b2000)
libva.so.2 => /usr/lib/x86_64-linux-gnu/libva.so.2 (0x00007f584f989000)
libva-drm.so.2 => /usr/lib/x86_64-linux-gnu/libva-drm.so.2 (0x00007f584f984000)
libva-x11.so.2 => /usr/lib/x86_64-linux-gnu/libva-x11.so.2 (0x00007f584f97a000)
libvdpau.so.1 => /usr/lib/x86_64-linux-gnu/libvdpau.so.1 (0x00007f584f974000)
libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007f584f837000)
libdrm.so.2 => /usr/lib/x86_64-linux-gnu/libdrm.so.2 (0x00007f584f823000)
libOpenCL.so.1 => /usr/lib/x86_64-linux-gnu/libOpenCL.so.1 (0x00007f584f618000)
libicuuc.so.66 => /usr/lib/x86_64-linux-gnu/libicuuc.so.66 (0x00007f584f432000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f584f24f000)
libmpg123.so.0 => /usr/lib/x86_64-linux-gnu/libmpg123.so.0 (0x00007f584f1ef000)
libvorbisfile.so.3 => /usr/lib/x86_64-linux-gnu/libvorbisfile.so.3 (0x00007f584f1e4000)
libfontconfig.so.1 => /usr/lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007f584f19d000)
libfreetype.so.6 => /usr/lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007f584f0de000)
libp11-kit.so.0 => /usr/lib/x86_64-linux-gnu/libp11-kit.so.0 (0x00007f584efa6000)
libidn2.so.0 => /usr/lib/x86_64-linux-gnu/libidn2.so.0 (0x00007f584ef85000)
libunistring.so.2 => /usr/lib/x86_64-linux-gnu/libunistring.so.2 (0x00007f584ee03000)
libtasn1.so.6 => /usr/lib/x86_64-linux-gnu/libtasn1.so.6 (0x00007f584eded000)
libnettle.so.7 => /usr/lib/x86_64-linux-gnu/libnettle.so.7 (0x00007f584edb3000)
libhogweed.so.5 => /usr/lib/x86_64-linux-gnu/libhogweed.so.5 (0x00007f584ed7b000)
libgmp.so.10 => /usr/lib/x86_64-linux-gnu/libgmp.so.10 (0x00007f584ecf5000)
libgcrypt.so.20 => /usr/lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007f584ebd7000)
libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007f584ebb4000)
libgssapi_krb5.so.2 => /usr/lib/x86_64-linux-gnu/libgssapi_krb5.so.2 (0x00007f584eb67000)
libsoxr.so.0 => /usr/lib/x86_64-linux-gnu/libsoxr.so.0 (0x00007f584eafc000)
libcairo-gobject.so.2 => /usr/lib/x86_64-linux-gnu/libcairo-gobject.so.2 (0x00007f584eaee000)
libgdk_pixbuf-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0 (0x00007f584eac6000)
libgio-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0 (0x00007f584e8e5000)
libpangocairo-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpangocairo-1.0.so.0 (0x00007f584e8d3000)
libpango-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpango-1.0.so.0 (0x00007f584e884000)
libffi.so.7 => /usr/lib/x86_64-linux-gnu/libffi.so.7 (0x00007f584e878000)
libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f584e803000)
libpixman-1.so.0 => /usr/lib/x86_64-linux-gnu/libpixman-1.so.0 (0x00007f584e75c000)
libpng16.so.16 => /usr/lib/x86_64-linux-gnu/libpng16.so.16 (0x00007f584e724000)
libxcb-shm.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-shm.so.0 (0x00007f584e71f000)
libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007f584e6f5000)
libxcb-render.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-render.so.0 (0x00007f584e6e6000)
libXrender.so.1 => /usr/lib/x86_64-linux-gnu/libXrender.so.1 (0x00007f584e4da000)
libXext.so.6 => /usr/lib/x86_64-linux-gnu/libXext.so.6 (0x00007f584e4c5000)
libogg.so.0 => /usr/lib/x86_64-linux-gnu/libogg.so.0 (0x00007f584e4b8000)
libnuma.so.1 => /usr/lib/x86_64-linux-gnu/libnuma.so.1 (0x00007f584e4ab000)
libXfixes.so.3 => /usr/lib/x86_64-linux-gnu/libXfixes.so.3 (0x00007f584e4a1000)
libicudata.so.66 => /usr/lib/x86_64-linux-gnu/libicudata.so.66 (0x00007f584c9e0000)
libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007f584c9b2000)
libuuid.so.1 => /lib/x86_64-linux-gnu/libuuid.so.1 (0x00007f584c9a9000)
libkrb5.so.3 => /usr/lib/x86_64-linux-gnu/libkrb5.so.3 (0x00007f584c8cc000)
libk5crypto.so.3 => /usr/lib/x86_64-linux-gnu/libk5crypto.so.3 (0x00007f584c899000)
libcom_err.so.2 => /lib/x86_64-linux-gnu/libcom_err.so.2 (0x00007f584c892000)
libkrb5support.so.0 => /usr/lib/x86_64-linux-gnu/libkrb5support.so.0 (0x00007f584c883000)
libgomp.so.1 => /usr/lib/x86_64-linux-gnu/libgomp.so.1 (0x00007f584c841000)
libgmodule-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgmodule-2.0.so.0 (0x00007f584c83b000)
libmount.so.1 => /lib/x86_64-linux-gnu/libmount.so.1 (0x00007f584c7db000)
libselinux.so.1 => /lib/x86_64-linux-gnu/libselinux.so.1 (0x00007f584c7ae000)
libresolv.so.2 => /lib/x86_64-linux-gnu/libresolv.so.2 (0x00007f584c792000)
libpangoft2-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0 (0x00007f584c779000)
libfribidi.so.0 => /usr/lib/x86_64-linux-gnu/libfribidi.so.0 (0x00007f584c75c000)
libthai.so.0 => /usr/lib/x86_64-linux-gnu/libthai.so.0 (0x00007f584c751000)
libharfbuzz.so.0 => /usr/lib/x86_64-linux-gnu/libharfbuzz.so.0 (0x00007f584c64c000)
libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007f584c644000)
libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007f584c63c000)
libkeyutils.so.1 => /lib/x86_64-linux-gnu/libkeyutils.so.1 (0x00007f584c635000)
libblkid.so.1 => /lib/x86_64-linux-gnu/libblkid.so.1 (0x00007f584c5de000)
libpcre2-8.so.0 => /usr/lib/x86_64-linux-gnu/libpcre2-8.so.0 (0x00007f584c54e000)
libdatrie.so.1 => /usr/lib/x86_64-linux-gnu/libdatrie.so.1 (0x00007f584c542000)
libgraphite2.so.3 => /usr/lib/x86_64-linux-gnu/libgraphite2.so.3 (0x00007f584c515000)
libbsd.so.0 => /usr/lib/x86_64-linux-gnu/libbsd.so.0 (0x00007f584c4fb000)
If you need to write your own -sys crate instead of using the existing one, you can use the pkg-config
thanks!!!!!!!!! I added the libraries in ffmpeg-sys-next and then my project which depends on ffmpeg-sys-next built correctly.
Why, though, I need for ffmpeg-sys-next to link with its dependencies? Why I cannot fill them later in my project? I understand that this is horrible, I'll definetely fill then in ffmpeg-sys-next already, but I'm curious why.
Also, your help made me fix the other problem of mine that you linked. It was the same problem: linking things in my lib, no ffmpeg-sys-next. If I remember correctly, on C++ I could do this, or I'm mistaken.
Anyways, you didn't get any errors because my ffmpeg-sys-next is not the same as the public one, I added new things, that's why it didn't link things correctly. I'm gonna make a pull request once things are working correctly.
the strange thing is that ffmpeg-sys-next built correctly without any of the dependencies. It's only when I link with my project that I get the error.
kornel
October 1, 2020, 4:56pm
7
Don't use println!("cargo:rustc-link-lib in your projects, unless you're writing a separate sys crate .
Instead, add libz-sys to your project as a dependency. It does extra work to ensure that zlib can be found and linked properly. Additionally, using a shared sys crate ensures the same library won't be loaded twice. It would be problematic if two different versions of zlib got pulled in by different crates, so it's helpful if everyone uses the same sys crate instead of their own linker flags.
guerlando:
Why, though, I need for ffmpeg-sys-next to link with its dependencies? Why I cannot fill them later in my project? I understand that this is horrible, I'll definetely fill then in ffmpeg-sys-next already, but I'm curious why.
The order in which things are linked actually matters. The rust toolchain tries to take care of it for you, but to do that, it needs to know the true dependencies.