BRANCH_coq = $(shell $(COQBIN)coqtop -v | head -1 | grep -E '(trunk|master)' \
	     | wc -l | sed 's/ *//g')

ifneq "$(BRANCH_coq)" "0"
BRANCH_coq = trunk
else
BRANCH_coq = $(shell $(COQBIN)coqtop -v | head -1 \
	     | sed 's/.*version \([0-9]\.[0-9]\)[^ ]* .*/v\1/')
endif

HASH_coq = $(shell echo Quit. | $(COQBIN)coqtop 2>/dev/null | head -1 \
	   | sed 's/^.*(\([a-f0-9]*\)).*/\1/' )

HASH_coq_v85beta1 = eaa3d0b15adf4eb11ffb00ab087746a5b15c4d5d
HASH_coq_v85beta2 = 94afd8996251c30d2188a75934487009538e1303

V=$(BRANCH_coq)
ifeq "$(HASH_coq)" "$(HASH_coq_v85beta1)"
V=v8.5beta1
$(error "$(V) not supported: From X Require Y does not find X.Z.Y, use 8.4 or 8.5 > beta2")
endif
ifeq "$(HASH_coq)" "$(HASH_coq_v85beta2)"
V=v8.5beta2
$(error "$(V) not supported: From X Require Y does not find X.Z.Y (in coqdep), use 8.4 or 8.5 > beta2")
endif