Mounting filesystem images vignette unclear

[JosiahParry]

The vignette for mounting file system images seems like it will help me understand how to build an R package for webr but im quite lost while reading it. It indicates that we should use rwasm::add_pkg() to build a package repo. Though the context is unclear.

rwasm/vignettes/mount-fs-image.Rmd

Lines 16 to 20 in c60e4eb

	To build an R package library image we must first build one or more Wasm R packages using `add_pkg()`. As an example, let's build a package with a few hard dependencies. Ensure that you are running R in an environment with access to Wasm development tools^[See the "Setting up the WebAssembly toolchain" section in `vignette("rwasm")` for further details.], then run:
	```{r eval=FALSE}
	rwasm::add_pkg("dplyr")
	```

Should the rwasm be installed from pak into a webr interpreter? If so, how is that done? Should rwasm be used from a normal R session and then the output added into an active webr session?

If additional context about where these commands should be ran that would be very helpful!

[georgestagg]

The vignette for mounting file system images seems like it will help me understand how to build an R package for webr but im quite lost while reading it.

Have you read the Getting Started document yet? It tries to lead you through creating a package repository and is targeted more towards beginners.

The "Mounting filesystem images" method is only really beneficial over creating a package repository if you have arbitrary data you'd like to include on the virtual filesystem. If you're only really interested in building R packages, you don't strictly need to build a full filesystem image with rwasm::make_vfs_library() and can do without the steps described in that vignette.

Should the rwasm be installed from pak into a webr interpreter?

No, rwasm should be installed in a traditional R system so that R packages can be cross-compiled for WebAssembly in an environment where the WebAssembly build tools are available. Hopefully, this is made clearer in the Getting Started document.

Should rwasm be used from a normal R session and then the output added into an active webr session?

Correct. Again, the Getting Started vignette describes both a "local testing" method and "static deployment" method to make the R packages available to webR.