On Mon, 2022-08-15 at 22:24 -0400, Dmitry Goncharov wrote: > make-4.3 lets the user control (via presence or absence of +) if a > particular sub-process should participate in the jobserver business. > The current master, on the other hand, is "everyting is up to the > sub-make". > E.g. > all:; make -C src > In the case of make-4.3 the sub-make does not participate. > In the case of master the sub-make participates.
I would be surprised if too many people are using this method, because it leads to a somewhat obscure warning from make and people generally don't like their build systems to show obscure warnings. If people want sub-makes to not participate in the jobserver the better way to do it is to add "-j1" explicitly to the sub-make command (although this also shows a warning, at least it's clear what it means and may be considered "documentation") or they manipulate the MAKEFLAGS variable to remove jobserver info. But, I do agree it's a change in behavior. I tried to describe this in the NEWS file but maybe it's too abstract for people to realize the significance.
