Found the following executable files:
  src/rust/target/release/build/crossbeam-utils-4cd39d7d9eddd4e1/build-script-build
  src/rust/target/release/build/crossbeam-utils-4cd39d7d9eddd4e1/build_script_build-4cd39d7d9eddd4e1
  src/rust/target/release/build/esaxx-rs-786e58892a3be59f/build-script-build
  src/rust/target/release/build/esaxx-rs-786e58892a3be59f/build_script_build-786e58892a3be59f
  src/rust/target/release/build/extendr-api-a7c46f83e542c0c5/build-script-build
  src/rust/target/release/build/extendr-api-a7c46f83e542c0c5/build_script_build-a7c46f83e542c0c5
  src/rust/target/release/build/extendr-ffi-20728be3ccf6dcb5/build-script-build
  src/rust/target/release/build/extendr-ffi-20728be3ccf6dcb5/build_script_build-20728be3ccf6dcb5
  src/rust/target/release/build/libc-8eac6875e9872b1d/build-script-build
  src/rust/target/release/build/libc-8eac6875e9872b1d/build_script_build-8eac6875e9872b1d
  src/rust/target/release/build/onig_sys-06c82491195dd7a4/build-script-build
  src/rust/target/release/build/onig_sys-06c82491195dd7a4/build_script_build-06c82491195dd7a4
  src/rust/target/release/build/paste-a084fc71b4dfe357/build-script-build
  src/rust/target/release/build/paste-a084fc71b4dfe357/build_script_build-a084fc71b4dfe357
  src/rust/target/release/build/portable-atomic-bf1487163738e2dc/build-script-build
  src/rust/target/release/build/portable-atomic-bf1487163738e2dc/build_script_build-bf1487163738e2dc
  src/rust/target/release/build/proc-macro2-d6751ecdfce7c625/build-script-build
  src/rust/target/release/build/proc-macro2-d6751ecdfce7c625/build_script_build-d6751ecdfce7c625
  src/rust/target/release/build/rayon-core-0c89fc8cdad5adf9/build-script-build
  src/rust/target/release/build/rayon-core-0c89fc8cdad5adf9/build_script_build-0c89fc8cdad5adf9
  src/rust/target/release/build/serde-7bc40781d7e3ec63/build-script-build
  src/rust/target/release/build/serde-7bc40781d7e3ec63/build_script_build-7bc40781d7e3ec63
  src/rust/target/release/build/serde_json-81dec0ffb83fa7ae/build-script-build
  src/rust/target/release/build/serde_json-81dec0ffb83fa7ae/build_script_build-81dec0ffb83fa7ae
  src/rust/target/release/build/thiserror-faa495cc12110ef7/build-script-build
  src/rust/target/release/build/thiserror-faa495cc12110ef7/build_script_build-faa495cc12110ef7
  src/rust/target/release/build/zerocopy-3dcc5d5744a539c3/build-script-build
  src/rust/target/release/build/zerocopy-3dcc5d5744a539c3/build_script_build-3dcc5d5744a539c3
Source packages should not contain undeclared executable files.
See section ‘Package structure’ in the ‘Writing R Extensions’ manual.