bindings.h:1:10: fatal error: 'btf.h' file not found

[yasin-cs-ko-ak]

❯ cargo build --examples
   Compiling bpf-sys v2.3.0 (/home/u1tron/Documents/Projects/eBPF/redbpf/bpf-sys)
error: failed to run custom build command for `bpf-sys v2.3.0 (/home/u1tron/Documents/Projects/eBPF/redbpf/bpf-sys)`

Caused by:
  process didn't exit successfully: `/home/u1tron/Documents/Projects/eBPF/redbpf/target/debug/build/bpf-sys-f6efd10e4f746fd1/build-script-build` (exit status: 101)
  --- stderr
  bindings.h:1:10: fatal error: 'btf.h' file not found
  bindings.h:1:10: fatal error: 'btf.h' file not found, err: true
  thread 'main' panicked at 'Unable to generate bindings: ()', bpf-sys/build.rs:23:10
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

I do have my header file in this directory/usr/include/uapi/linux/btf.h. But it's not compiling properly.
and also I am installed cargo-bpf with this command cargo install cargo-bpf --no-default-features --features=llvm13,command-line
any thoughts?

[bendahl]

Same issue here. I'm on Ubuntu 22.04 and have btf.h in /usr/include/linux/btf.h as well as /usr/include/bpf/btf.h. The command llvm-config --version returns 14.0.0. So the default llvm version installed on Ubuntu 22 is newer than required as per the specs. I don't think that this is an issue though.

Any help/input would be highly appreciated. Thanks in advance! Let me know if you need any more information.

[rsdy]

https://github.com/foniod/redbpf#building-redbpf-from-source Please make sure you sync the submodules and try again. Let me know if build still fails then!

@bendahl RedBPF on master will not work with LLVM 14. You will need to check out the branch for #316 to test that.

[bendahl]

@rsdy Thanks for the super quick reply!

I just gave this a try (using the llvm14-branch of nbaksalyar/redbpf). Unfortunately, the issue persists. So I'm guessing there is something wrong in my environment. Besides the two locations that I mentioned earlier, I also noticed, that another btf.h is generated by the build process in ./target/debug/build/libbpf-sys-7dd166d0a8efc198/out/include/bpf. This is also picked up correctly when browsing the code in my local IDE.

I will make sure to check out the other link you provided to see whether I'm missing some important step.

[bendahl]

Quick update: This was totally my fault. I missed the important step of syncing/updating the git submodules (as described in the document you linked above). Doing this and using the llvm14 branch worked.

Thank you so much!

[yasin-cs-ko-ak]

@bendahl If you could provide me the steps that you did to solve this problem, that would be very much helpful.
ex: how to sync the git sub-modules?

[yasin-cs-ko-ak]

@bendahl I hope you followed these steps

$ git clone https://github.com/foniod/redbpf.git
$ cd redbpf
$ git submodule sync
$ git submodule update --init
$ cargo build
$ cargo build --examples

[rsdy]

@yasin-cs-ko-ak

$ git submodule sync
$ git submodule update --init

are the 2 commands specifically you'll need. Let me know how it goes.

[yasin-cs-ko-ak]

@rsdy
when I followed those steps you mentioned above I have encountered with these errors and warning.
$ cargo build

warning: field is never read: `flags`
   --> redbpf/src/symbols.rs:110:5
    |
110 |     flags: i32,
    |     ^^^^^^^^^^
    |
    = note: `#[warn(dead_code)]` on by default
note: `CacheEntry` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
   --> redbpf/src/symbols.rs:106:10
    |
106 | #[derive(Debug)]
    |          ^^^^^
    = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: `redbpf` (lib) generated 1 warning
   Compiling redbpf-probes v2.3.0 (/home/u1tron/redbpf/redbpf-probes)
   Compiling probes v0.1.0 (/home/u1tron/redbpf/redbpf-tools/probes)
   Compiling redbpf-tools v0.1.0 (/home/u1tron/redbpf/redbpf-tools)
   Compiling example-probes v0.1.0 (/home/u1tron/redbpf/examples/example-probes)
error: failed to run custom build command for `redbpf-tools v0.1.0 (/home/u1tron/redbpf/redbpf-tools)`

Caused by:
  process didn't exit successfully: `/home/u1tron/redbpf/target/debug/build/redbpf-tools-3d0d971cdb53b260/build-script-build` (exit status: 101)
  --- stderr
  thread 'main' panicked at 'couldn't compile probes: InvalidLLVMVersion("LLVM version that cargo-bpf linked to (13.0) < LLVM version that rustc depends on (14.0). You should re-build cargo-bpf with LLVM version (14.0), or downgrade rustc that uses LLVM version (13.0)")', redbpf-tools/build.rs:16:10
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
warning: build failed, waiting for other jobs to finish...

[yasin-cs-ko-ak]

Do I have to use this build command instead of that one
cargo build --no-default-features --features=llvm13,command-line ?

[bendahl]

@yasin-cs-ko-ak Seems like I'm a bit late to the party... However, to answer your question: Yes, I used the following commands to update the submodules:

git submodule sync
git submodule update --init

I then ran cargo build and cargo build --examples. Both commands worked fine.

My setup is as follows:

• OS: Ubuntu 22.04
• Rust version: 1.61.0 (fe5b13d68 2022-05-18)
• llvm version: 14.0.0

Due to the fact that I'm using llvm 14 I had to switch to nbaksalyar/redbpf:llvm14. As mentioned by @rsdy there is a pull request regarding llvm 14 support (see #316).

I hope this helps!

[yasin-cs-ko-ak]

@bendahl Well, I have tried with that repository mentioned above. I still got the same error as previous and then I decided to try again with different method. I downloaded that repository as ZIP and then initiated using git init and then ran that two commands.
But still

   Compiling toml_edit v0.2.1
error: No suitable version of LLVM was found system-wide or pointed
              to by LLVM_SYS_140_PREFIX.
       
              Consider using `llvmenv` to compile an appropriate copy of LLVM, and
              refer to the llvm-sys documentation for more information.
       
              llvm-sys: https://crates.io/crates/llvm-sys
              llvmenv: https://crates.io/crates/llvmenv
   --> /home/u1tron/.cargo/registry/src/github.com-1ecc6299db9ec823/llvm-sys-140.0.0/src/lib.rs:487:1
    |
487 | / std::compile_error!(concat!(
488 | |     "No suitable version of LLVM was found system-wide or pointed
489 | |        to by LLVM_SYS_",
490 | |     env!("CARGO_PKG_VERSION_MAJOR"),
...   |
497 | |        llvmenv: https://crates.io/crates/llvmenv"
498 | | ));
    | |__^

error: could not compile `llvm-sys` due to previous error
warning: build failed, waiting for other jobs to finish...

I think there is something wrong with my LLVM version.
If you need any details of my system, kindly let me know.
Thanks for the help!

[yasin-cs-ko-ak]

@rsdy @bendahl
For your information.
This is my rustc and llvm configs

❯ rustc -vV
rustc 1.61.0 (fe5b13d68 2022-05-18)
binary: rustc
commit-hash: fe5b13d681f25ee6474be29d748c65adcd91f69e
commit-date: 2022-05-18
host: x86_64-unknown-linux-gnu
release: 1.61.0
LLVM version: 14.0.0

❯ llvm-config --version
13.0.1

and also I was looking at this. This might be helpful for this. #213

[rsdy]

@yasin-cs-ko-ak Please try the branch with LLVM14 support among the PRs. master doesn't support LLVM14 at this point.