Expand upon an existing comment in the GNUmakefile.

diff --git a/GNUmakefile b/GNUmakefile
index 331c65cd70c266c3cef55ca9a6ed7278b1a94bee..cf7ab221fbc7cf04668564ba2f54fa6af5f040c9 100644 (file)
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -98,7 +98,7 @@ $(PN).aux: $(SRCS)
 
 # The pipe below indicates an "order-only dependency" on the aux file.
 # Without it, every compilation of $(PN).tex would produce a new
-# $(PN).aux, and thus $(PN).bbl would be rebuild. This in turn causes
+# $(PN).aux, and thus $(PN).bbl would be rebuilt. This in turn causes
 # $(PN).pdf to appear out-of-date, which leads to a recompilation of
 # $(PN).tex... and so on. The order-only dependency means we won't
 # rebuild $(PN).bbl if $(PN).aux changes.
@@ -108,7 +108,9 @@ $(PN).aux: $(SRCS)
 #
 # If the $BIBS variable is undefined, we presume that there are no
 # references and create an empty bbl file. Otherwise, we risk trying
-# to run biblatex on an aux file containing no citations.
+# to run biblatex on an aux file containing no citations. If you do
+# define $BIBS but don't cite anything, you'll run into a similar
+# problem. Don't do that.
 #
 $(PN).bbl: $(SRCS) | $(PN).aux
 ifdef BIBS