catman.mk: build-catman-troff: Fail if troff(1) writes to stderr

Signed-off-by: Alejandro Colomar <alx@kernel.org>

diff --git a/share/mk/build/catman.mk b/share/mk/build/catman.mk
index 4d0683737221d218182169295b7f90c21c7733a5..a64bf514cff66787789fec2d2d61c511c2ab4b7c 100644 (file)
--- a/share/mk/build/catman.mk
+++ b/share/mk/build/catman.mk
@@ -77,7 +77,8 @@ $(_CATMAN_troff): %.cat.troff: %.eqn | $$(@D)/
 
 $(_CATMAN_set): %.cat.set: %.cat.troff | $$(@D)/
        $(info  TROFF   $@)
-       $(TROFF) -T$(NROFF_OUT_DEVICE) $(TROFFFLAGS) <$< >$@
+       $(TROFF) -T$(NROFF_OUT_DEVICE) $(TROFFFLAGS) <$< 2>&1 >$@ \
+       | ( ! $(GREP) ^ )
 
 $(_CATMAN): %.cat: %.cat.set | $$(@D)/
        $(info  GROTTY  $@)