cargo install mdcat fails with llvm error

[getaaron]

cargo install mdcat

Compiles many dependencies successfully, then fails on onig_sys:

   Compiling hyper-tls v0.3.2
   Compiling reqwest v0.9.20
   Compiling onig_sys v69.2.0
error: failed to run custom build command for `onig_sys v69.2.0`

Caused by:
  process didn't exit successfully: `/tmp/cargo-install57Mtrg/release/build/onig_sys-c69a530df1a224ce/build-script-build` (exit code: 101)
--- stdout
cargo:warning=couldn't execute `llvm-config --prefix` (error: No such file or directory (os error 2))
cargo:warning=set the LLVM_CONFIG_PATH environment variable to a valid `llvm-config` executable

--- stderr
thread 'main' panicked at 'Unable to find libclang: "couldn\'t find any valid shared libraries matching: [\'libclang.so\', \'libclang-*.so\', \'libclang.so.*\'], set the `LIBCLANG_PATH` environment variable to a path where one of these files can be found (invalid: [])"', src/libcore/result.rs:999:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.

warning: build failed, waiting for other jobs to finish...
error: failed to compile `mdcat v0.13.0`, intermediate artifacts can be found at `/tmp/cargo-install57Mtrg`

Caused by:
  build failed

Running this on Debian Linux (Debian 10, aka "Buster")

[swsnr]

I’ve also seen this. It’s an issue with onig sys; there’s already a ticket in the rust-onig Github repo.

Not sure if we can fix this in this here; if so I’d appreciate a pull request because I have no time to look at this.

[getaaron]

Fixed this with:

sudo apt-get install llvm
sudo apt-get install clang
cargo install mdcat

Will open a README PR

[swsnr]

for reference rust-onig/rust-onig#109

[swsnr]

Thanks to #131 mdcat 0.16.0 now builds without Clang and LLVM.

[getaaron]

Nice!