--- a/debian/patches/reproducible-build.patch	1970-01-01 01:00:00.000000000 +0100
--- b/debian/patches/reproducible-build.patch	2020-05-15 10:04:43.856783106 +0100
@@ -0,0 +1,88 @@
+Description: Make the build reproducible
+Author: Chris Lamb <lamby@debian.org>
+Last-Update: 2020-05-15
+
+--- tree-puzzle-5.3~rc16+dfsg.orig/src/puzzle1.c
++++ tree-puzzle-5.3~rc16+dfsg/src/puzzle1.c
+@@ -3204,7 +3204,9 @@ void initeps(FILE *ofp)
+ 		fprintf(ofp, "%%%%Creator: %s (version %s%s)\n", PACKAGE, VERSION, ALPHA);
+ #	endif
+ 	fprintf(ofp, "%%%%Title: Likelihood Mapping Analysis\n");
+-	fprintf(ofp, "%%%%CreationDate: %s", asctime(localtime(&Starttime)) );
++	if (getenv("SOURCE_DATE_EPOCH") == NULL) {
++		fprintf(ofp, "%%%%CreationDate: %s", asctime(localtime(&Starttime)) );
++	}
+ 	fprintf(ofp, "%%%%DocumentFonts: Helvetica\n");
+ 	fprintf(ofp, "%%%%DocumentNeededFonts: Helvetica\n");
+ 	fprintf(ofp, "%%%%EndComments\n");
+@@ -3826,6 +3828,10 @@ void timestamp(FILE* ofp)
+ 	timespan = difftime(Stoptime, Starttime);
+ 	cpuspan  = ((double) (Stopcpu - Startcpu) / CLOCKS_PER_SEC);
+ 	fprintf(ofp, "\n\nTIME STAMP\n\n");
++	if (getenv("SOURCE_DATE_EPOCH") != NULL) {
++		fprintf(ofp, "Date and time: (reproducible build)");
++		return;
++	}
+ 	fprintf(ofp, "Date and time: %s", asctime(localtime(&Starttime)) );
+ 	fprintf(ofp, "Runtime (excl. input) : %.0f seconds (= %.1f minutes = %.1f hours)\n",
+ 		timespan, timespan/60., timespan/3600.);
+@@ -8924,33 +8930,35 @@ fprintf(stderr, "PPP1: %d (%s:%d)\n", PP
+ 		fprintftimespan(stdout, PStepStoptime, Stoptime, Starttime, "Pstep -> end");
+ #	endif /* DEBUG_PRINTTIMES */
+ 
+-	/* runtime message */
+-	fprintf(STDOUT,
+-		"The parameter estimation took %.2f seconds (= %.2f minutes = %.2f hours)\n",
+-			difftime(PEstStoptime, PEstStarttime), difftime(PEstStoptime, PEstStarttime)/60.,
+-			difftime(PEstStoptime, PEstStarttime)/3600.);
+-	if (puzzlemode == QUARTPUZ && typ_optn == TREERECON_OPTN) {
++	if (getenv("SOURCE_DATE_EPOCH") == NULL) {
++		/* runtime message */
+ 		fprintf(STDOUT,
+-			"The ML step took              %.2f seconds (= %.2f minutes = %.2f hours)\n",
+-				difftime(MLstepStoptime, MLstepStarttime), difftime(MLstepStoptime, MLstepStarttime)/60.,
+-				difftime(MLstepStoptime, MLstepStarttime)/3600.);
+-		fprintf(STDOUT,
+-			"The puzzling step took        %.2f seconds (= %.2f minutes = %.2f hours)\n",
+-				difftime(PStepStoptime, PStepStarttime), difftime(PStepStoptime, PStepStarttime)/60.,
+-				difftime(PStepStoptime, PStepStarttime)/3600.);
+-	}
+-	fprintf(STDOUT, 
+-		"The computation took %.2f seconds (= %.2f minutes = %.2f hours)\n",
+-			difftime(Stoptime, Starttime), difftime(Stoptime, Starttime)/60.,
+-			difftime(Stoptime, Starttime)/3600.);
+-	fprintf(STDOUT, 
+-		"     including input %.2f seconds (= %.2f minutes = %.2f hours)\n",
+-			fulltime, fulltime/60., fulltime/3600.);
++			"The parameter estimation took %.2f seconds (= %.2f minutes = %.2f hours)\n",
++				difftime(PEstStoptime, PEstStarttime), difftime(PEstStoptime, PEstStarttime)/60.,
++				difftime(PEstStoptime, PEstStarttime)/3600.);
++		if (puzzlemode == QUARTPUZ && typ_optn == TREERECON_OPTN) {
++			fprintf(STDOUT,
++				"The ML step took              %.2f seconds (= %.2f minutes = %.2f hours)\n",
++					difftime(MLstepStoptime, MLstepStarttime), difftime(MLstepStoptime, MLstepStarttime)/60.,
++					difftime(MLstepStoptime, MLstepStarttime)/3600.);
++			fprintf(STDOUT,
++				"The puzzling step took        %.2f seconds (= %.2f minutes = %.2f hours)\n",
++					difftime(PStepStoptime, PStepStarttime), difftime(PStepStoptime, PStepStarttime)/60.,
++					difftime(PStepStoptime, PStepStarttime)/3600.);
++		}
++		fprintf(STDOUT, 
++			"The computation took %.2f seconds (= %.2f minutes = %.2f hours)\n",
++				difftime(Stoptime, Starttime), difftime(Stoptime, Starttime)/60.,
++				difftime(Stoptime, Starttime)/3600.);
++		fprintf(STDOUT, 
++			"     including input %.2f seconds (= %.2f minutes = %.2f hours)\n",
++				fulltime, fulltime/60., fulltime/3600.);
+ #ifdef TIMEDEBUG
+-	fprintf(STDOUT, 
+-		"and %.0f seconds CPU time (= %.2f minutes = %.2f hours)\n\n",
+-			fullcpu, fullcpu/60., fullcpu/3600.);
++		fprintf(STDOUT, 
++			"and %.0f seconds CPU time (= %.2f minutes = %.2f hours)\n\n",
++				fullcpu, fullcpu/60., fullcpu/3600.);
+ #endif /* TIMEDEBUG */
++	}
+ 
+ 	/* free memory */
+ 	memcleanup();
--- a/debian/patches/series	2020-05-15 09:38:09.193050479 +0100
--- b/debian/patches/series	2020-05-15 09:44:49.247986506 +0100
@@ -3,3 +3,4 @@
 spelling.patch
 fix-mpi3-build.patch
 update_test_results.patch
+reproducible-build.patch