diff -Nru gap-guava-3.13+ds/debian/changelog gap-guava-3.13+ds/debian/changelog
--- gap-guava-3.13+ds/debian/changelog	2016-04-22 20:30:05.000000000 +0000
+++ gap-guava-3.13+ds/debian/changelog	2016-12-31 01:50:14.000000000 +0000
@@ -1,3 +1,19 @@
+gap-guava (3.13+ds-2) unstable; urgency=medium
+
+  * FTBFS fix release (Closes: #849661), discard inert but now causing failure
+    (and certainly forgotten) command in the target `all' in src/Makefile.
+  * Debianization:
+    - debian/control:
+      - Standards Version, bump to 3.9.8;
+    - debian/patches/*:
+      - d/p/upstream-fix-src-make_machinery-disambiguation-bug_849661.patch,
+        introduce;
+      - Origin fields, correct;
+    - debian/tests/*:
+      - d/t/makecheck.tst, typo.
+
+ -- Jerome Benoit <calculus@rezozer.net>  Sat, 31 Dec 2016 01:50:14 +0000
+
 gap-guava (3.13+ds-1) unstable; urgency=medium
 
   * New upstream release:
diff -Nru gap-guava-3.13+ds/debian/control gap-guava-3.13+ds/debian/control
--- gap-guava-3.13+ds/debian/control	2016-04-22 20:30:05.000000000 +0000
+++ gap-guava-3.13+ds/debian/control	2016-12-31 00:00:50.000000000 +0000
@@ -7,7 +7,7 @@
  debhelper (>= 9), autoconf, automake,
  gap (>=4r8p3), gap-dev (>=4r8p3), gap-gapdoc (>=1.5.1-2),
  texlive-latex-recommended, texlive-fonts-recommended, texlive-latex-extra
-Standards-Version: 3.9.7
+Standards-Version: 3.9.8
 Homepage: http://www.gap-system.org/Packages/guava.html
 Vcs-Git: https://anonscm.debian.org/git/debian-science/packages/gap-guava.git
 Vcs-Browser: https://anonscm.debian.org/cgit/debian-science/packages/gap-guava.git
diff -Nru gap-guava-3.13+ds/debian/patches/series gap-guava-3.13+ds/debian/patches/series
--- gap-guava-3.13+ds/debian/patches/series	2016-04-22 20:30:05.000000000 +0000
+++ gap-guava-3.13+ds/debian/patches/series	2016-12-31 01:06:40.000000000 +0000
@@ -1,2 +1,3 @@
+upstream-fix-src-make_machinery-disambiguation-bug_849661.patch
 upstream-doc-bibdata-sanitization.patch
 debianization.patch
diff -Nru gap-guava-3.13+ds/debian/patches/upstream-doc-bibdata-sanitization.patch gap-guava-3.13+ds/debian/patches/upstream-doc-bibdata-sanitization.patch
--- gap-guava-3.13+ds/debian/patches/upstream-doc-bibdata-sanitization.patch	2016-04-22 20:30:05.000000000 +0000
+++ gap-guava-3.13+ds/debian/patches/upstream-doc-bibdata-sanitization.patch	2016-12-31 01:36:26.000000000 +0000
@@ -4,7 +4,7 @@
  composed documentation is comparable to the one composed for GAP itself;
  some metadata has been updated; meant to be submitted to the upstream
  maintainer.
-Origin: debian
+Origin: vendor, Debian
 Forwarded: https://github.com/osj1961/guava/pull/19
 Author: Jerome Benoit <calculus@rezozer.net>
 Last-Update: 2016-04-21
diff -Nru gap-guava-3.13+ds/debian/patches/upstream-fix-src-make_machinery-disambiguation-bug_849661.patch gap-guava-3.13+ds/debian/patches/upstream-fix-src-make_machinery-disambiguation-bug_849661.patch
--- gap-guava-3.13+ds/debian/patches/upstream-fix-src-make_machinery-disambiguation-bug_849661.patch	1970-01-01 00:00:00.000000000 +0000
+++ gap-guava-3.13+ds/debian/patches/upstream-fix-src-make_machinery-disambiguation-bug_849661.patch	2016-12-31 01:42:57.000000000 +0000
@@ -0,0 +1,20 @@
+Description: upstream: fix: src/: make machinery: disambiguation
+ Discard inert (and certainly forgotten) command in src/Makefile that causes
+ failure with shells whose `cd' command admits at most one path as argument
+ (e.g., bash >= 4.4.5); meant to be submitted to the upstream maintainer.
+Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=849661
+Origin: vendor, Debian
+Forwarded: https://github.com/osj1961/guava/pull/26
+Author: Jerome Benoit <calculus@rezozer.net>
+Last-Update: 2016-12-31
+
+--- a/src/Makefile
++++ b/src/Makefile
+@@ -11,7 +11,6 @@
+ .PHONY: all $(SUBDIRS)
+ 
+ all :	$(FILES)
+-	cd leon make
+ 
+ leonconv: leonconv.c
+ 	$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -o leonconv leonconv.c
diff -Nru gap-guava-3.13+ds/debian/tests/makecheck.tst gap-guava-3.13+ds/debian/tests/makecheck.tst
--- gap-guava-3.13+ds/debian/tests/makecheck.tst	2016-04-22 20:30:05.000000000 +0000
+++ gap-guava-3.13+ds/debian/tests/makecheck.tst	2016-12-30 23:58:30.000000000 +0000
@@ -10,7 +10,7 @@
 >   if ForAny( ["desauto", "leonconv", "wtdist"],
 >       f -> Filename( path, f ) = fail
 >       ) then
->     Print( "#I  Cannot found at least one of the C code programs.\n" );
+>     Print( "#I  Cannot find at least one of the C code programs.\n" );
 >     answer := false;
 >   fi;
 >   return answer;