Based on the APRILTAG_SRC environment variable, the apriltag implementation is chosen.

If APRILTAG_SRC is not set, a precompiled apriltag library will be used with details coming from pkg-config. Further environment variables can be used to tune this, as specified in the pkg-config crate docs.

Otherwise, APRILTAG_SRC is assumed to specify a directory with the source code of the apriltag library. This source code is then compiled and statically linked into the rust crate.

Example:

export APRILTAG_SRC=$HOME/Documents/other-peoples-src/apriltag
cargo test

Regenerate src/lib.rs with:

./run-bindgen.sh

Currently, the bindings are built against commit 756423674639e1bd3c38503c34a1e39cec57cd0a from https://github.com/AprilRobotics/apriltag .