diff --git a/sys/unix/Makefile.src b/sys/unix/Makefile.src
index 19f41ca81..f6b9371bc 100644
--- a/sys/unix/Makefile.src
+++ b/sys/unix/Makefile.src
@@ -1,5 +1,5 @@
 #	NetHack Makefile.
-# NetHack 3.6  Makefile.src	$NHDT-Date: 1519228664 2018/02/21 15:57:44 $  $NHDT-Branch: githash $:$NHDT-Revision: 1.51 $
+# NetHack 3.6  Makefile.src	$NHDT-Date: 1520201829 2018/03/04 22:17:09 $  $NHDT-Branch: NetHack-3.6.0 $:$NHDT-Revision: 1.52 $
 
 # Root of source tree:
 NHSROOT=..
@@ -606,13 +606,13 @@ tile.c: ../win/share/tilemap.c $(HACK_H)
 #	file far more complex.  Since "hack.h" depends on most of the include
 #	files, we kludge around this by making date.h dependent on hack.h,
 #	even though it doesn't include this file.
+#	Do NOT include ../dat/gitinfo.txt as either a prerequisite or target.
+#	'makedefs -v' processes it when present and ignores it if not.
 #
 #	hack.h depends on makedefs' output, so we know makedefs will be
 #	up to date before being executed
 ../include/date.h:	$(VERSOURCES) $(HACK_H)
-	if [[ ! -f ../dat/gitinfo.txt ]]; then \
-	  (cd ..;perl -IDEVEL/hooksdir -MNHgithook -e '&NHgithook::nhversioning') || true; \
-	fi
+	-$(SHELL) ../sys/unix/gitinfo.sh  #../dat/gitinfo.txt for 'makedefs -v'
 	../util/makedefs -v
 
 
diff --git a/sys/unix/gitinfo.sh b/sys/unix/gitinfo.sh
new file mode 100755
index 000000000..72d300454
--- /dev/null
+++ b/sys/unix/gitinfo.sh
@@ -0,0 +1,25 @@
+#!/bin/sh
+# NetHack 3.6  gitinfo.sh	$NHDT-Date: 1520201830 2018/03/04 22:17:10 $  $NHDT-Branch: NetHack-3.6.0 $:$NHDT-Revision: 1.0 $
+
+# if dat/gitinfo.txt doesn't exist, try to make one; called from Makefile.src
+
+#
+# gitinfo.txt is used during development to augment the version number
+# (for nethack's 'v' command) with more specific information.  That is not
+# necessary when building a released version and it is perfectly OK for
+# this script to be skipped or to run but fail to generate dat/gitinfo.txt.
+#
+
+# try to figure out where we are: top, one level down (expected), or sys/unix
+prefix=.
+if [ -f ../sys/unix/gitinfo.sh ]; then prefix=..; fi
+if [ -f ../../sys/unix/gitinfo.sh ]; then prefix=../..; fi
+
+# try to run a perl script which is part of nethack's git repository
+if [[ ! -f $prefix/dat/gitinfo.txt ]]; then
+  ( cd $prefix; \
+    perl -IDEVEL/hooksdir -MNHgithook -e '&NHgithook::nhversioning' \
+      2> /dev/null ) \
+  || true
+fi
+exit 0