This blog is updated daily.
A general description is here.
If R uses custom binary type in its ‘.Platform$pkgType’ then ‘R CMD INSTALL --build’ will produce ‘<package>_<ver>_R_<system>-<build>.tar.xz’ binary files. Please note that future versions may use ‘.zstd’ compression by default so package tooling should support any of the above mentioned extensions.
The ‘"Built"’ column returned by ‘available.packages()’ and ‘old.packages()’ now contains the full value of the ‘"Built"’ entry (if present) in the ‘DESCRIPTION’ file. Previously, only the R version from the ‘"Built"’ entry was returned.
If the timestamp passed as -built-timestamp to ‘R CMD INSTALL’ is in RFC-822 form (with time-zone offset) it will be converted to ISO UTC form to conform to the format used by R for purposes described above. (PR#19037, thanks to Dirk Eddelbuettel)