Generally, you should just reproduce the same installation steps as for the original installation: upgrade from your system's package manager, or re-run the binary installer. Opam will automatically update its internal repository at ~/.opam on first run if needed (if using our installer script, a backup can be made automatically). Jan 27, 2021 · Just tried to use JetPack 4.5. Install and initial config had no issues. However, installing new packages does not work the same as the previous releases. My scripts use “sudo apt-get” and they all result in “Package xxx is not available, but is referred to by another package.” I have used this same script for at least the last 2 JetPack releases without issue. What has changed? Package php5-gd is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source installation path not writable R, unable to update packages (4) I had same problem, and the answer is to give Root Access to R i.e run R or Rstudio as administrator . check this question out: installed directory not writable, cannot update packages 'boot', 'class', 'KernSmooth', 'mgcv', 'nnet', 'rpart', 'spatial'