r-cran-listenv 0.8.0-1 (ppc64el binary) in ubuntu focal

 List environments are environments that have list-like properties. For
 instance, the elements of a list environment are ordered and can be accessed
 and iterated over using index subsetting, e.g. 'x <- listenv(a=1, b=2); for (i
 in seq_along(x)) x[[i]] <- x[[i]]^2; y <- as.list(x)'.