R: Apply the most recent snapshot to the library

restore {packrat} | R Documentation

## Apply the most recent snapshot to the library

### Description

Applies the most recent snapshot to the project's private library.

### Usage

    restore(project = NULL, overwrite.dirty = FALSE, prompt = interactive(),
      dry.run = FALSE, restart = !dry.run)

### Arguments

`project` | The project directory. When in packrat mode, if this is `NULL`, then the directory associated with the current packrat project is used. Otherwise, the project directory specified is used.
`overwrite.dirty` | A dirty package is one that has been changed since the last snapshot or restore. Packrat will leave these alone by default. If you want to guarantee that `restore` will put you in the exact state represented by the snapshot being applied, use `overwrite.dirty = TRUE`.
`prompt` | `TRUE` to prompt before performing potentially destructive changes (package removals or downgrades); `FALSE` to perform these operations without confirmation.
`dry.run` | If `TRUE`, compute the changes to your packrat state that would be made if a restore was performed, without actually executing them.
`restart` | If `TRUE`, restart the R session after restoring.

### Details

`restore` works by adding, removing, and changing packages so that the set of installed packages and their versions matches the snapshot exactly.

There are three common use cases for `restore`:

- Hydrate: Use `restore` after copying a project to a new machine to populate the library on that machine.

- Sync: Use `restore` to apply library changes made by a collaborator to your own library. (In general, you want to run `restore` whenever you pick up a change to `packrat.lock`)

- Rollback: Use `restore` to undo accidental changes made to the library since the last snapshot.

`restore` cannot make changes to packages that are currently loaded. If changes are necessary to currently loaded packages, you will need to restart R to apply the changes (`restore` will let you know when this is necessary). It is recommended that you do this as soon as possible, because any library changes made between running `restore` and restarting R will be lost.

### Note

`restore` can be destructive; it will remove packages that were not in the snapshot, and it will replace newer packages with older versions if that's what the snapshot indicates. `restore` will warn you before attempting to remove or downgrade a package (if `prompt` is `TRUE`), but will always perform upgrades and new installations without prompting.

`restore` works only on the private package library created by packrat; if you have other libraries on your path, they will be unaffected.

The `restart` parameter will only result in a restart of R when the R environment packrat is running within makes available a restart function via `getOption("restart")`.

### See Also

`snapshot`, the command that creates the snapshots applied with `restore`.

`status` to view the differences between the most recent snapshot and the library.

[Package packrat version 0.4.9 Index]