--- /dev/null
+--- a/build_tools/make_build_h
++++ b/build_tools/make_build_h
+@@ -5,6 +5,14 @@
+ OS=`uname -s`
+ USER=`id | awk -F")" '{print $1}'| awk -F"(" '{print $2}' | sed 's/\\\\/\\\\\\\\/g'`
+ DATE=`date -u "+%Y-%m-%d %H:%M:%S"`
++if [ -n "${SOURCE_DATE_EPOCH}" ]; then
++ # building reproducibly, faking some data
++ HOSTNAME='buildd.debian.org'
++ KERNEL='unknown'
++ MACHINE='unknown'
++ USER='nobody'
++ DATE=`date -u "+%Y-%m-%d %H:%M:%S" -d @${SOURCE_DATE_EPOCH}`
++fi
+ cat << END
+ /*
+ * build.h
+--- a/Makefile
++++ b/Makefile
+@@ -465,7 +465,7 @@
+ @echo "<docs xmlns:xi=\"http://www.w3.org/2001/XInclude\">" >> $@
+ @for x in $(MOD_SUBDIRS); do \
+ printf "$$x " ; \
+- for i in `find $$x -name '*.c'`; do \
++ for i in `find $$x -name '*.c' | LC_ALL=C sort`; do \
+ $(AWK) -f build_tools/get_documentation $$i >> $@ ; \
+ done ; \
+ done