https://psalm.dev/r/7106f13383

in PHP 8 vsprintf will never return false, but in PHP 7 it will.
As discussed in #9877 (comment) the stubs will never fall back to the callmap - this makes declaring different return/param types between PHP versions impossible in psalm.

I suggest to change it to fall back from the stubs to the callmap if the param/return type is not declared in the stubs (but is in the callmap)

Also somehow related to #9843 since atm no consistency checking happens in-between the different versions of the callmap and the stubs either