asap_sketchlib build fails because of missing protoc compiler

[milindsrivastava1997]

Error:

error: failed to run custom build command for `asap_sketchlib v0.1.0 (https://github.com/ProjectASAP/asap_sketchlib#fcc89922)`

Caused by:
  process didn't exit successfully: `/tmp/repro-proto/target/debug/build/asap_sketchlib-b149d3063ab98094/build-script-build` (exit status: 101)
  --- stderr

  thread 'main' (138720) panicked at /users/milindsr/.cargo/git/checkouts/asap_sketchlib-4ee86c13981a5592/fcc8992/build.rs:18:6:
  prost_build failed to compile proto files: Custom { kind: NotFound, error: "Could not find `protoc`. If `protoc` is installed, try setting the `PROTOC` environment variable to the path of the `protoc` binary. To install it on Debian, run `apt-get install protobuf-compiler`. It is also available at https://github.com/protocolbuffers/protobuf/releases  For more information: https://docs.rs/prost-build/#sourcing-protoc" }
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Steps to reproduce:

1. cargo init /tmp/repro-proto && cd /tmp/repro-proto
2. cargo add --git https://github.com/ProjectASAP/asap_sketchlib
3. cargo build

[GordonYuanyc]

can you try:
apt-get update && apt-get install -y --no-install-recommends protobuf-compiler
and see if that build can work?
This is just a temporary workaround.