For an installation of an operating system to be successful, packages must recognize and correctly respect alternate root (/) file systems, such as a Solaris Live Upgrade inactive boot environment.
Packages can include absolute paths in their pkgmap file (package map). If these files exist, they are written relative to the -R option of the pkgadd command. Packages that contain both absolute and relative (relocatable) paths can be installed to an alternative root (/) file system as well. $PKG_INSTALL_ROOT is prepended to both absolute and relocatable files so all paths are resolved properly when being installed by pkgadd.