Thanks Paul, that's part way to the solution but I couldn't find a way to make it work generically. The good news is that it's fixed internally for 4.4.1, the bad news is that finding a solution that translates to older versions is hard at least for me. I was able to come up with a Linux-only solution which is good enough for my use case. It's shown here in case useful for anyone else:
# Determine whether a -j flag was used explicitly. Do not remove the space in "-j ". jval := $(filter -j%,$(subst -j ,-j,$(shell tr '\0' ' ' </proc/$$PPID/cmdline))) I'm only interested in $(jval) as a boolean but it does seem to derive the numeric value pretty reliably. FWIW my use case is undoing old hacks which force -j in recursive use and lead to "jobserver unavailable" and "jobserver reset" messages. Deriving -j is needed for transitional compatibility. David On Thu, May 23, 2024 at 12:21 PM Paul Smith <psm...@gnu.org> wrote: > On Thu, 2024-05-23 at 11:34 -0400, DSB wrote: > > "To access the pipe you must parse the 'MAKEFLAGS' variable and look > > for the argument string '--jobserver-auth=R,W'" > > I don't have time to test this right now but I think in 4.2 you have to > look at the shell variable, not the makefile variable. > > E.g. > > $(info $(shell echo $$MAKEFLAGS)) > >
