Don't use current user, hostname and build time

but parse debian/changelog instead to work towards reproducibility.

Thanks: Ben Hutchings for pointing this out

debian/rules

 #!/usr/bin/make -f
 
 DEB_RELEASE=$(shell dpkg-parsechangelog -SVersion | sed 's/[^-]\+-//')
-DEB_BUILDHOST=$(shell hostname)
-DEB_BUILDDATE=$(shell date +"%F-%T")
-DEB_BUILDUSER=${USER}
+DEB_BUILDDATE=$(shell dpkg-parsechangelog -SDate)
+DEB_BUILDUSER=$(shell dpkg-parsechangelog -SMaintainer)
 
 ifneq (,$(findstring $(DEB_HOST_ARCH_OS), linux))
   ifneq (,$(findstring $(DEB_HOST_ARCH), i386 amd64))
@@ -83,7 +82,7 @@ else
 endif
 
 DEB_CONFIGURE_EXTRA_ARGS :=      \
-	--with-packager="$(DEB_BUILDUSER) $(DEB_BUILDDATE) $(DEB_BUILDHOST)" \
+	--with-packager="$(DEB_BUILDUSER) $(DEB_BUILDDATE)" \
 	--with-packager-version="$(DEB_RELEASE)" \
 	--with-default-editor="sensible-editor" \
 	--disable-silent-rules   \