Build Error

[geomlattice]

Hi I attempted:

git clone https://github.com/pdf-rs/encoding.git
cd encoding
rustc build.rs
./build

and got the error:

thread 'main' panicked at build.rs:8:61:
called `Result::unwrap()` on an `Err` value: NotPresent
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Normal build gives the following error message

cargo build --release
warning: unused import: `Path`
 --> build.rs:4:17
  |
4 | use std::path::{Path, PathBuf};
  |                 ^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

warning: unused import: `std::iter::once`
 --> build.rs:5:5
  |
5 | use std::iter::once;
  |     ^^^^^^^^^^^^^^^

warning: unused `Result` that must be used
  --> build.rs:14:5
   |
14 |     writeln!(glyph_list, "[");
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: this `Result` may be an `Err` variant, which should be handled
   = note: `#[warn(unused_must_use)]` on by default
   = note: this warning originates in the macro `writeln` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: unused `Result` that must be used
  --> build.rs:28:9
   |
28 |         writeln!(glyph_list, "    ({:?}, {:?}),", name, unicode);
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: this `Result` may be an `Err` variant, which should be handled
   = note: this warning originates in the macro `writeln` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: unused `Result` that must be used
  --> build.rs:30:5
   |
30 |     writeln!(glyph_list, "]");
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: this `Result` may be an `Err` variant, which should be handled
   = note: this warning originates in the macro `writeln` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: `pdf_encoding` (build script) generated 5 warnings
   Compiling pdf_encoding v0.4.0 (/home/ubuntu/rustdf/encoding)
error: failed to run custom build command for `pdf_encoding v0.4.0 (/home/ubuntu/rustdf/encoding)`

Caused by:
  process didn't exit successfully: `/home/ubuntu/rustdf/encoding/target/release/build/pdf_encoding-2380ac3d71333ac9/build-script-build` (exit status: 101)
  --- stdout
  cargo:rerun-if-changed=build.rs
  cargo:rerun-if-changed=/home/ubuntu/rustdf/encoding/agl-aglfn/glyphlist.txt

  --- stderr
  thread 'main' panicked at build.rs:15:49:
  called `Result::unwrap()` on an `Err` value: Os { code: 2, kind: NotFound, message: "No such file or directory" }

What can be done to help this build?