Compiling ffmpeg-sys v3.4.1
     Running `C:\_work\2018\moderncap\target\debug\build\ffmpeg-sys-ea48ecdf7ecc4000\build-script-build`
error: failed to run custom build command for `ffmpeg-sys v3.4.1`
process didn't exit successfully: `C:\_work\2018\moderncap\target\debug\build\ffmpeg-sys-ea48ecdf7ecc4000\build-script-build` (exit code: 101)
--- stderr
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Command { command: "\"pkg-config\" \"--libs\" \"--cflags\" \"libavformat\"", cause: Os { code: 2, kind: NotFound, message: "The system cannot find the file specified." } }', libcore\result.rs:1009:5
stack backtrace:
   0: <std::sync::mpsc::select::Select as core::fmt::Debug>::fmt
   1: <std::sys::windows::dynamic_lib::DynamicLibrary as core::ops::drop::Drop>::drop
   2: std::panicking::take_hook
   3: std::panicking::take_hook
   4: std::panicking::rust_panic_with_hook
   5: std::panicking::begin_panic_fmt
   6: rust_begin_unwind
   7: core::panicking::panic_fmt
   8: core::result::unwrap_failed<pkg_config::Error>
             at \libcore\macros.rs:26
   9: core::result::Result<pkg_config::Library, pkg_config::Error>::unwrap<pkg_config::Library,pkg_config::Error>
             at \libcore\result.rs:808
  10: build_script_build::main
             at .\build.rs:518
  11: std::rt::lang_start::{{closure}}<()>
             at \libstd\rt.rs:74
  12: std::panicking::update_panic_count
  13: _rust_maybe_catch_panic
  14: std::rt::lang_start_internal
  15: std::rt::lang_start<()>
             at \libstd\rt.rs:74
  16: main
  17: invoke_main
             at f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:78
  18: invoke_main
             at f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:78
  19: BaseThreadInitThunk
  20: RtlUserThreadStart