Comment (by Roland Haas):

Something like this however may kind of work, by checking for failure:

$(shell : $(OBJS))
ifeq ($(.SHELLSTATUS),0)
  OBJS-too-long := 0
else
  OBJS-too-long := 1
endif

which just tries to execute the : (true) command.

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2908/cactus-fixed-arg-list-too-long-error