Coming from renv • rpix

renv and Pixi solve the same problem: giving each project its own, recorded set of packages. If you know renv, most of rpix will feel familiar.

What’s different

Pixi manages R itself, and the system libraries packages need, such as GDAL. With renv, you install those yourself.
Packages come from conda-forge, as binaries for every platform, rather than from CRAN. The most used CRAN packages are there; for most of the others, and for packages from GitHub, Pixi can build them from source (experimental). See Finding packages, and How many packages you can use.
Each environment has its own R. You start R through Pixi rather than activating a library in the R you already have. See How rpix works.
The lock file is always up to date. There’s no snapshot step: adding or removing a package updates pixi.lock.

renv’s functions in rpix

renv	rpix or Pixi
`renv::init()`	`rpix::use_pixi()`
`renv::install("dplyr")`	`rpix::pixi_add("dplyr")`
`renv::remove("dplyr")`	`rpix::pixi_remove("dplyr")`
`renv::snapshot()`	Not needed
`renv::restore()`	`rpix::pixi_install()`
`renv::status()`	`rpix::pixi_sitrep()`, which says when `pixi.lock` is out of date, or `rpix::pixi_install(locked = TRUE)`, which fails then
`renv::update()`	`rpix::pixi_update()`, within the versions `pixi.toml` allows, or `rpix::pixi_upgrade()` to raise those
`renv.lock`	`pixi.toml` and `pixi.lock`

Moving a project from renv

renv keeps rpix out of the project’s own R, so set the project up from another R session, e.g. your usual R outside the project. use_pixi() notices renv.lock, and offers to move the packages over first:

rpix::use_pixi(path = "~/myproject")
#> ℹ This project uses renv ('renv.lock').
#> ? Would you like to move its packages to Pixi, and turn renv off?
#> 1: Yes
#> 2: No

Yes runs pixi_import_renv(), which:

adds the packages in renv.lock to pixi.toml, at least at their locked versions, with the lock file’s version of R. Use versions = "exact" for the locked versions themselves, where conda-forge has them.
adds only the packages that nothing else in the lock file needs: the ones your project uses. Pixi installs what they need.
adds packages from GitHub too, built from source at the commit renv.lock records, and offers to build CRAN packages that aren’t on conda-forge from source (see When a package isn’t on conda-forge). Building from source is experimental, so it says which packages it built.
lists packages it can’t add: those in a subfolder of a GitHub repository, from other sources such as GitLab, and those that aren’t on conda-forge or bioconda and can’t be built.
turns renv off, by removing source("renv/activate.R") from .Rprofile. Delete renv.lock and the renv folder when you no longer need them.

Then open the project in your IDE, set up with use_pixi(ide = ) (see Using rpix with an IDE).

For other options, e.g. the locked versions themselves, answer no, and run rpix::pixi_import_renv(versions = "exact", path = "~/myproject") afterwards.