This resolved (and explained) this issue. I hadn't realized PNGs had embedded timestamps. Thank you, Gerard
________________________________________ From: Niels Thykier <ni...@thykier.net> Sent: Monday, February 19, 2018 3:41 PM To: Weatherby,Gerard; debian-dpkg@lists.debian.org Subject: Re: dpkg-buildpackage modifying *png file Weatherby,Gerard: > I'm using dpkg-buildpackage -b -uc -us to prepare a *deb package for a > private repository. > > It seems to be modifying a byte PNG image file, as indicated by "cmp" > > ./relax/docs/html/icons/index.png > ./debian/relax/usr/software/relax/docs/html/icons/index.png differ: byte 82, > line 3 > > My debian/install file looks like: > relax /usr/software > > ?I'd appreciate a hint as to what's going on. > > > [...] Hi, I suspect it is not dpkg-buildpackage but the tools run from debian/rules. If you use the minimal debian/rules based on dh, then it will run "dh_strip_nondeterminism" which among other will attempt to normalize metadata in png files. Assuming my guesses are correct so far, you can disable dh_strip_nondeterminism by inserting an empty override for it. Assuming no existing override, this should be as simple as: echo "# Disable dh_strip_nondeterminism" >> debian/rules echo "override_dh_strip_nondeterminism:" >> debian/rules Thanks, ~Niels
