Substrate build failure with `--runtime-benchmarks` flag

Question

git checkout 91b97b016618fcc515f55a15b1f008b68e13f5a2
cargo check --features runtime-benchmarks

error: failed to run custom build command for `sc-network-bitswap v0.10.0-dev (/root/code/self/substrate/client/network/bitswap)`

Caused by:
  process didn't exit successfully: `/root/code/self/substrate/target/debug/build/sc-network-bitswap-23c560e6e0d6a1a2/build-script-build` (exit status: 101)
  --- stderr
  thread 'main' panicked at '
  Could not find `protoc` installation and this build crate cannot proceed without
  this knowledge. If `protoc` is installed and this crate had trouble finding
  it, you can set the `PROTOC` environment variable with the specific path to your
  installed `protoc` binary.

  For more information: https://docs.rs/prost-build/#sourcing-protoc
  ', /root/.cargo/registry/src/github.com-1ecc6299db9ec823/prost-build-0.11.1/src/lib.rs:1227:10
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Answer 1

You posted the solution to your own question:

Could not find `protoc` installation and this build crate cannot proceed without
this knowledge. If `protoc` is installed and this crate had trouble finding
it, you can set the `PROTOC` environment variable with the specific path to your 
installed `protoc` binary.

As this is saying. Please install protoc and make sure that the binary is available in the global PATH or set the PROTOC environment variable pointing to the binary.

Answer 2

Looks like you are missing a crate dependency....

Try installing this: sudo apt install --assume-yes git clang curl libssl-dev llvm libudev-dev make protobuf-compiler