Why does readLAS() not work in older versions of lidR anymore?

Question

I am unfortunately dependent on an older version (4.0.4) of the lidR package due to a package dependency. Strangely enough, the import of LAS files with readLAS() no longer works since a system update. The problem seems to occur with all older package versions except for the current version. Below you will find a code example that produces the error for me.

# install lidR package version 4.0.4
remotes::install_version("lidR", "4.0.4")

# load package
library(lidR)

# get example file path
LASfile <- system.file("extdata", "Megaplot.laz", package = "lidR")

# read las file
las <- readLAS(LASfile)

Error: Not compatible with requested type: [type=character; target=double].

Is this behavior intentional or am I doing something wrong?

I am using R version 4.4.1 under Ubuntu 22.04.4 LTS.

Answer 1

The backward incompatibility arises from changes to CRAN policies, which required us to remove certain C++ dependencies from the rlas package, responsible for reading and writing LAS/LAZ files. To preserve functionality, we had to make internal changes in rlas that introduced backward incompatibilities. However, this shouldn't affect users as long as they keep their packages up to date.

In your case, the issue seems to stem from using an outdated version of lidR with the newer version of rlas. Downgrading to an older version of rlas might resolve the issue, but I’m more concerned that you feel the need to stick with version 4.0.4. It's quite old, and numerous bugs have since been fixed. I suspect your issue might lie elsewhere.