People that installed the base-devel group-package (before it became a meta-package) won't get the actual "base-devel" package itself installed on their machine until they explicitly (re-)install it. This may cause some regressions. For instance, since the "base-devel" package isn't /listed as/ installed on the system, pacman won't prevent users to remove packages it depends on.
I draft a news about this, don't hesitate to give me your thoughts :)
# Switch to the base-devel meta-package requires manual intervention
The `base-devel` group-package has recently been replaced by a meta-package of the same name. People that had the `base-devel` group-package installed (meaning people that installed `base-devel` before February 2nd) have to explicitly re-install it to get the new `base-devel` package installed on their system: ``` pacman -Syu base-devel ```