Preflight setup before installing R packages

Why preflight?

A new GNU/Linux user often meets system requirements only after something has already failed. The better workflow is to check the setup first, use binary R packages where possible, and install source build tools only when source packages are needed.

sysreqr is a zero-runtime-dependency helper for that workflow. It does not run sudo, edit operating system repositories, or install system packages. It prints commands and writes files that the user, or their administrator, can review.

Understand the platform

sysreqr tries to detect the current platform automatically, but examples and reproducible scripts should usually pass a platform string.

detect_package_manager("ubuntu-24.04")
#> [1] "apt"
resolve_platform("noble")
#> $os
#> [1] "linux"
#> 
#> $distro
#> [1] "ubuntu"
#> 
#> $version
#> [1] "24.04"
#> 
#> $codename
#> [1] "noble"
#> 
#> $package_manager
#> [1] "apt"
#> 
#> $ppm_binary_url
#> [1] "noble"
#> 
#> $supported
#> [1] TRUE
#> 
#> $label
#> [1] "Ubuntu 24.04"
#> 
#> attr(,"class")
#> [1] "sysreqr_platform"

Common platform strings:

Distribution	`<distro>-<version>`	Codename alias
Ubuntu	`ubuntu-22.04`	`jammy`
Ubuntu	`ubuntu-24.04`	`noble`
Ubuntu	`ubuntu-26.04`	`resolute`
Debian	`debian-12`	`bookworm`
Debian	`debian-13`	`trixie`
RHEL family	`rockylinux-9`, `redhat-9`
Fedora	`fedora-40`
openSUSE/SLE	`opensuse156`, `sle-15.6`

Start with setup advice

setup_advice() produces a practical checklist for a Linux platform.

setup_advice(platform = "ubuntu-24.04")

The advice has four layers:

Posit Package Manager, when a binary repository URL is known.
Source build tools such as r-base-dev, compilers, make, and pkg-config.
Optional R Project operating system repository commands for supported Ubuntu, Debian, and Fedora systems.
Package-specific system requirements when package names are supplied.

The R Project operating system repository layer is optional because it changes the operating system repository configuration. It is most relevant when the system R version is too old. It is not the first fix for every missing library.

To include package-specific requirements:

setup_advice(
  packages = c("xml2", "curl"),
  platform = "ubuntu-24.04"
)

To write a reviewable shell script:

setup_advice(
  packages = c("xml2", "curl"),
  platform = "ubuntu-24.04",
  script = "setup-sysreqr.sh"
)

The script contains source build tools and package system requirements as active commands. Optional operating system repository commands are included as comments because they should be reviewed first.

Use Posit Package Manager

Binary R packages are the simplest way to avoid source compilation problems.

Build a Posit Package Manager repository URL:

ppm_repo(platform = "ubuntu-24.04")
#> [1] "https://packagemanager.posit.co/cran/__linux__/noble/latest"

Preview the .Rprofile lines that would point R at that repository:

use_ppm(platform = "ubuntu-24.04", dry_run = TRUE)
#> [1] "options("                                                                  
#> [2] "  repos = c("                                                              
#> [3] "    CRAN = \"https://packagemanager.posit.co/cran/__linux__/noble/latest\""
#> [4] "  )"                                                                       
#> [5] ")"

use_ppm() does not edit files unless dry_run = FALSE.

When network access is available, these helpers query Posit Package Manager support and system requirement data live:

check_ppm("ubuntu-22.04")
ppm_platforms()
ppm_sysreqs(c("xml2", "curl"), platform = "ubuntu-22.04")

Check packages before installing

check_packages() returns a sysreqr_plan. The plan is a data frame with the R package, system requirement, installable system package, install script, platform, package manager, installed status when available, source, confidence, and notes.

plan <- check_packages(
  c("xml2", "curl"),
  platform = "ubuntu-22.04"
)
plan
#> System requirement preflight
#> 
#> Platform: Ubuntu 22.04
#> Package manager: apt
#> Backend: bundled
#> 
#> R packages checked:
#>   curl, xml2
#> 
#> System packages to install: 
#>   libcurl4-openssl-dev  needed by: curl  status: unknown
#>   libssl-dev  needed by: curl  status: unknown
#>   libxml2-dev  needed by: xml2  status: unknown
#> 
#> Run:
#>   sudo apt-get update
#>   sudo apt-get install -y libcurl4-openssl-dev libssl-dev libxml2-dev

Turn the plan into common outputs:

install_command(plan)
#> [1] "sudo apt-get update"                                                
#> [2] "sudo apt-get install -y libcurl4-openssl-dev libssl-dev libxml2-dev"

write_install_script(plan, "install-sysreqs.sh")
dockerfile(plan)
github_actions(plan)

Write files for review or automation:

write_report(plan, "SYSREQS.md")
write_json(plan, "sysreqs.json")

Create a message for an administrator:

admin_request(plan)

Inspect or explain a plan:

as_data_frame(plan)
as_install_plan(plan)
is_sysreqr_plan(plan)
explain(plan)

Pick a backend

check_packages() accepts four backend modes.

backend = "auto" uses bundled data for simple, known CRAN packages on apt platforms, then Package Manager, then pak when possible.
backend = "bundled" uses only the static database shipped with the installed sysreqr release. Currently optimized for apt.
backend = "ppm" uses the Posit Package Manager API when network access is available.
backend = "pak" uses pak::pkg_sysreqs() when pak is installed.

sysreqr has zero runtime dependencies. Optional live backends (ppm, pak) are used only when requested and available.