The previous version (0.2.2) failed to build against math/R 4.6.0.
PRENV, PREXPR, and Rf_findVar are non-API entry points whose
declarations are no longer available in R 4.6.0's installed headers.
Version 0.2.3 rewrites the C implementation on top of the rlang C
library to comply with R's public C API.
Release notes: https://github.com/hadley/lazyeval/releases/tag/v0.2.3