This uses pkgDepTopoSort internally so that the package dependency tree is determined, and then packages are unloaded in the reverse order. Some packages don't unload successfully for a variety of reasons. Several known packages that have this problem are identified internally and not unloaded. Currently, these are glue, rlang, ps, ellipsis, and, processx.

  dontTry = NULL,
  doSort = TRUE,
  verbose = getOption("Require.verbose")



A character vector of packages to detach. Will be topologically sorted unless doSort is FALSE.


A character vector of packages to not try. This can be used by a user if they find a package fails in attempts to unload it, e.g., "ps"


If TRUE (the default), then the pkgs will be topologically sorted. If FALSE, then it won't. Useful if the pkgs are already sorted.


Numeric or logical indicating how verbose should the function be. If -1 or -2, then as little verbosity as possible. If 0 or FALSE, then minimal outputs; if 1 or TRUE, more outputs; 2 even more. NOTE: in Require function, when verbose >= 2, the return object will have an attribute: attr(.., "Require") which has lots of information about the processes of the installs.


A numeric named vector, with names of the packages that were attempted. 2 means the package was successfully unloaded, 1 it was tried, but failed, 3 it was in the search path and was detached and unloaded.