Diff of the two buildlogs:

--
--- b1/build.log	2025-01-28 10:44:10.575940309 +0000
+++ b2/build.log	2025-01-28 10:46:23.437964642 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Mon Jan 27 22:43:13 -12 2025
-I: pbuilder-time-stamp: 1738060993
+I: Current time: Wed Jan 29 00:44:21 +14 2025
+I: pbuilder-time-stamp: 1738061061
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/trixie-reproducible-base.tgz]
 I: copying local configuration
@@ -24,52 +24,84 @@
 dpkg-source: info: applying Check_for_greyscale_when_small_image_uses_palette.patch
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/8738/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/21463/tmp/hooks/D01_modify_environment starting
+debug: Running on virt64c.
+I: Changing host+domainname to test build reproducibility
+I: Adding a custom variable just for the fun of it...
+I: Changing /bin/sh to bash
+'/bin/sh' -> '/bin/bash'
+lrwxrwxrwx 1 root root 9 Jan 28 10:44 /bin/sh -> /bin/bash
+I: Setting pbuilder2's login shell to /bin/bash
+I: Setting pbuilder2's GECOS to second user,second room,second work-phone,second home-phone,second other
+I: user script /srv/workspace/pbuilder/21463/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/21463/tmp/hooks/D02_print_environment starting
 I: set
-  BUILDDIR='/build/reproducible-path'
-  BUILDUSERGECOS='first user,first room,first work-phone,first home-phone,first other'
-  BUILDUSERNAME='pbuilder1'
-  BUILD_ARCH='armhf'
-  DEBIAN_FRONTEND='noninteractive'
-  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=3 '
-  DISTRIBUTION='trixie'
-  HOME='/root'
-  HOST_ARCH='armhf'
+  BASH=/bin/sh
+  BASHOPTS=checkwinsize:cmdhist:complete_fullquote:extquote:force_fignore:globasciiranges:globskipdots:hostcomplete:interactive_comments:patsub_replacement:progcomp:promptvars:sourcepath
+  BASH_ALIASES=()
+  BASH_ARGC=()
+  BASH_ARGV=()
+  BASH_CMDS=()
+  BASH_LINENO=([0]="12" [1]="0")
+  BASH_LOADABLES_PATH=/usr/local/lib/bash:/usr/lib/bash:/opt/local/lib/bash:/usr/pkg/lib/bash:/opt/pkg/lib/bash:.
+  BASH_SOURCE=([0]="/tmp/hooks/D02_print_environment" [1]="/tmp/hooks/D02_print_environment")
+  BASH_VERSINFO=([0]="5" [1]="2" [2]="37" [3]="1" [4]="release" [5]="arm-unknown-linux-gnueabihf")
+  BASH_VERSION='5.2.37(1)-release'
+  BUILDDIR=/build/reproducible-path
+  BUILDUSERGECOS='second user,second room,second work-phone,second home-phone,second other'
+  BUILDUSERNAME=pbuilder2
+  BUILD_ARCH=armhf
+  DEBIAN_FRONTEND=noninteractive
+  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=4 '
+  DIRSTACK=()
+  DISTRIBUTION=trixie
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=arm
+  HOST_ARCH=armhf
   IFS=' 	
   '
-  INVOCATION_ID='5ccb1a2a28304cd6b69bd92e4ad02415'
-  LANG='C'
-  LANGUAGE='en_US:en'
-  LC_ALL='C'
-  MAIL='/var/mail/root'
-  OPTIND='1'
-  PATH='/usr/sbin:/usr/bin:/sbin:/bin:/usr/games'
-  PBCURRENTCOMMANDLINEOPERATION='build'
-  PBUILDER_OPERATION='build'
-  PBUILDER_PKGDATADIR='/usr/share/pbuilder'
-  PBUILDER_PKGLIBDIR='/usr/lib/pbuilder'
-  PBUILDER_SYSCONFDIR='/etc'
-  PPID='8738'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=efbc4f8248264acaa4cae84135744463
+  LANG=C
+  LANGUAGE=it_CH:it
+  LC_ALL=C
+  MACHTYPE=arm-unknown-linux-gnueabihf
+  MAIL=/var/mail/root
+  OPTERR=1
+  OPTIND=1
+  OSTYPE=linux-gnueabihf
+  PATH=/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/i/capture/the/path
+  PBCURRENTCOMMANDLINEOPERATION=build
+  PBUILDER_OPERATION=build
+  PBUILDER_PKGDATADIR=/usr/share/pbuilder
+  PBUILDER_PKGLIBDIR=/usr/lib/pbuilder
+  PBUILDER_SYSCONFDIR=/etc
+  PIPESTATUS=([0]="0")
+  POSIXLY_CORRECT=y
+  PPID=21463
   PS4='+ '
-  PWD='/'
-  SHELL='/bin/bash'
-  SHLVL='2'
-  SUDO_COMMAND='/usr/bin/timeout -k 18.1h 18h /usr/bin/ionice -c 3 /usr/bin/nice /usr/sbin/pbuilder --build --configfile /srv/reproducible-results/rbuild-debian/r-b-build.OUh6kJHp/pbuilderrc_Xyxy --distribution trixie --hookdir /etc/pbuilder/first-build-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/trixie-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.OUh6kJHp/b1 --logfile b1/build.log zopfli_1.0.3-3.dsc'
-  SUDO_GID='110'
-  SUDO_UID='103'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  _='/usr/bin/systemd-run'
-  http_proxy='http://10.0.0.15:3142/'
+  PWD=/
+  SHELL=/bin/bash
+  SHELLOPTS=braceexpand:errexit:hashall:interactive-comments:posix
+  SHLVL=3
+  SUDO_COMMAND='/usr/bin/timeout -k 24.1h 24h /usr/bin/ionice -c 3 /usr/bin/nice -n 11 /usr/bin/unshare --uts -- /usr/sbin/pbuilder --build --configfile /srv/reproducible-results/rbuild-debian/r-b-build.OUh6kJHp/pbuilderrc_kngm --distribution trixie --hookdir /etc/pbuilder/rebuild-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/trixie-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.OUh6kJHp/b2 --logfile b2/build.log zopfli_1.0.3-3.dsc'
+  SUDO_GID=113
+  SUDO_UID=107
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  _='I: set'
+  http_proxy=http://10.0.0.15:3142/
 I: uname -a
-  Linux virt32z 6.1.0-30-armmp-lpae #1 SMP Debian 6.1.124-1 (2025-01-12) armv7l GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-30-arm64 #1 SMP Debian 6.1.124-1 (2025-01-12) aarch64 GNU/Linux
 I: ls -l /bin
   lrwxrwxrwx 1 root root 7 Nov 22 14:40 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/8738/tmp/hooks/D02_print_environment finished
+I: user script /srv/workspace/pbuilder/21463/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -135,7 +167,7 @@
 Get: 28 http://deb.debian.org/debian trixie/main armhf intltool-debian all 0.35.0+20060710.6 [22.9 kB]
 Get: 29 http://deb.debian.org/debian trixie/main armhf po-debconf all 1.0.21+nmu1 [248 kB]
 Get: 30 http://deb.debian.org/debian trixie/main armhf debhelper all 13.23 [919 kB]
-Fetched 19.6 MB in 2s (11.4 MB/s)
+Fetched 19.6 MB in 1s (32.7 MB/s)
 Preconfiguring packages ...
 Selecting previously unselected package sensible-utils.
 (Reading database ... 
(Reading database ... 5%
(Reading database ... 10%
(Reading database ... 15%
(Reading database ... 20%
(Reading database ... 25%
(Reading database ... 30%
(Reading database ... 35%
(Reading database ... 40%
(Reading database ... 45%
(Reading database ... 50%
(Reading database ... 55%
(Reading database ... 60%
(Reading database ... 65%
(Reading database ... 70%
(Reading database ... 75%
(Reading database ... 80%
(Reading database ... 85%
(Reading database ... 90%
(Reading database ... 95%
(Reading database ... 100%
(Reading database ... 19568 files and directories currently installed.)
@@ -270,7 +302,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/zopfli-1.0.3/ && env PATH="/usr/sbin:/usr/bin:/sbin:/bin:/usr/games" HOME="/nonexistent/first-build" dpkg-buildpackage -us -uc -b && env PATH="/usr/sbin:/usr/bin:/sbin:/bin:/usr/games" HOME="/nonexistent/first-build" dpkg-genchanges -S  > ../zopfli_1.0.3-3_source.changes
+I: user script /srv/workspace/pbuilder/21463/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/21463/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/zopfli-1.0.3/ && env PATH="/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/i/capture/the/path" HOME="/nonexistent/second-build" dpkg-buildpackage -us -uc -b && env PATH="/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/i/capture/the/path" HOME="/nonexistent/second-build" dpkg-genchanges -S  > ../zopfli_1.0.3-3_source.changes
 dpkg-buildpackage: info: source package zopfli
 dpkg-buildpackage: info: source version 1.0.3-3
 dpkg-buildpackage: info: source distribution unstable
@@ -280,7 +316,7 @@
  debian/rules clean
 dh  clean
    dh_auto_clean
-	make -j3 clean
+	make -j4 clean
 make[1]: Entering directory '/build/reproducible-path/zopfli-1.0.3'
 rm -f zopflipng zopfli obj/src/zopfli/blocksplitter.o obj/src/zopfli/cache.o obj/src/zopfli/deflate.o obj/src/zopfli/gzip_container.o obj/src/zopfli/hash.o obj/src/zopfli/katajainen.o obj/src/zopfli/lz77.o obj/src/zopfli/squeeze.o obj/src/zopfli/tree.o obj/src/zopfli/util.o obj/src/zopfli/zlib_container.o obj/src/zopfli/zopfli_lib.o obj/src/zopfli/zopfli_bin.o obj/src/zopflipng/lodepng/lodepng.o obj/src/zopflipng/lodepng/lodepng_util.o obj/src/zopflipng/zopflipng_lib.o obj/src/zopflipng/zopflipng_bin.o libzopfli*
 make[1]: Leaving directory '/build/reproducible-path/zopfli-1.0.3'
@@ -292,11 +328,12 @@
    debian/rules override_dh_auto_build
 make[1]: Entering directory '/build/reproducible-path/zopfli-1.0.3'
 dh_auto_build
-	make -j3 "INSTALL=install --strip-program=true"
+	make -j4 "INSTALL=install --strip-program=true"
 make[2]: Entering directory '/build/reproducible-path/zopfli-1.0.3'
 cc -W -Wall -Wextra -ansi -pedantic -lm -O2 -Wno-unused-function -fPIC -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/zopfli-1.0.3=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -c src/zopfli/blocksplitter.c -o obj/src/zopfli/blocksplitter.o
 cc -W -Wall -Wextra -ansi -pedantic -lm -O2 -Wno-unused-function -fPIC -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/zopfli-1.0.3=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -c src/zopfli/cache.c -o obj/src/zopfli/cache.o
 cc -W -Wall -Wextra -ansi -pedantic -lm -O2 -Wno-unused-function -fPIC -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/zopfli-1.0.3=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -c src/zopfli/deflate.c -o obj/src/zopfli/deflate.o
+cc -W -Wall -Wextra -ansi -pedantic -lm -O2 -Wno-unused-function -fPIC -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/zopfli-1.0.3=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -c src/zopfli/gzip_container.c -o obj/src/zopfli/gzip_container.o
 src/zopfli/cache.c: In function 'ZopfliInitCache':
 src/zopfli/cache.c:36:51: warning: format '%lu' expects argument of type 'long unsigned int', but argument 3 has type 'size_t' {aka 'unsigned int'} [-Wformat=]
    36 |         "Error: Out of memory. Tried allocating %lu bytes of memory.\n",
@@ -304,7 +341,6 @@
       |                                                   |
       |                                                   long unsigned int
       |                                                 %u
-cc -W -Wall -Wextra -ansi -pedantic -lm -O2 -Wno-unused-function -fPIC -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/zopfli-1.0.3=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -c src/zopfli/gzip_container.c -o obj/src/zopfli/gzip_container.o
 cc -W -Wall -Wextra -ansi -pedantic -lm -O2 -Wno-unused-function -fPIC -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/zopfli-1.0.3=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -c src/zopfli/hash.c -o obj/src/zopfli/hash.o
 cc -W -Wall -Wextra -ansi -pedantic -lm -O2 -Wno-unused-function -fPIC -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/zopfli-1.0.3=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -c src/zopfli/katajainen.c -o obj/src/zopfli/katajainen.o
 cc -W -Wall -Wextra -ansi -pedantic -lm -O2 -Wno-unused-function -fPIC -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/zopfli-1.0.3=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -c src/zopfli/lz77.c -o obj/src/zopfli/lz77.o
@@ -326,17 +362,17 @@
 ar rcs libzopflipng.a obj/src/zopflipng/lodepng/lodepng.o obj/src/zopflipng/lodepng/lodepng_util.o obj/src/zopflipng/zopflipng_lib.o
 make[2]: Leaving directory '/build/reproducible-path/zopfli-1.0.3'
 dh_auto_build -- zopflipng
-	make -j3 "INSTALL=install --strip-program=true" zopflipng
+	make -j4 "INSTALL=install --strip-program=true" zopflipng
 make[2]: Entering directory '/build/reproducible-path/zopfli-1.0.3'
 make[2]: 'zopflipng' is up to date.
 make[2]: Leaving directory '/build/reproducible-path/zopfli-1.0.3'
 dh_auto_build -- libzopfli
-	make -j3 "INSTALL=install --strip-program=true" libzopfli
+	make -j4 "INSTALL=install --strip-program=true" libzopfli
 make[2]: Entering directory '/build/reproducible-path/zopfli-1.0.3'
 cc obj/src/zopfli/blocksplitter.o obj/src/zopfli/cache.o obj/src/zopfli/deflate.o obj/src/zopfli/gzip_container.o obj/src/zopfli/hash.o obj/src/zopfli/katajainen.o obj/src/zopfli/lz77.o obj/src/zopfli/squeeze.o obj/src/zopfli/tree.o obj/src/zopfli/util.o obj/src/zopfli/zlib_container.o obj/src/zopfli/zopfli_lib.o -W -Wall -Wextra -ansi -pedantic -lm -O2 -Wno-unused-function -fPIC -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/zopfli-1.0.3=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -shared -Wl,-soname,libzopfli.so.1 -o libzopfli.so.1.0.3 -Wl,-z,relro
 make[2]: Leaving directory '/build/reproducible-path/zopfli-1.0.3'
 dh_auto_build -- libzopflipng
-	make -j3 "INSTALL=install --strip-program=true" libzopflipng
+	make -j4 "INSTALL=install --strip-program=true" libzopflipng
 make[2]: Entering directory '/build/reproducible-path/zopfli-1.0.3'
 g++ obj/src/zopfli/blocksplitter.o obj/src/zopfli/cache.o obj/src/zopfli/deflate.o obj/src/zopfli/gzip_container.o obj/src/zopfli/hash.o obj/src/zopfli/katajainen.o obj/src/zopfli/lz77.o obj/src/zopfli/squeeze.o obj/src/zopfli/tree.o obj/src/zopfli/util.o obj/src/zopfli/zlib_container.o obj/src/zopfli/zopfli_lib.o obj/src/zopflipng/lodepng/lodepng.o obj/src/zopflipng/lodepng/lodepng_util.o obj/src/zopflipng/zopflipng_lib.o -W -Wall -Wextra -ansi -pedantic -lm -O2 -Wno-unused-function -fPIC -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/zopfli-1.0.3=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security --shared -Wl,-soname,libzopflipng.so.1 -o libzopflipng.so.1.0.3 -Wl,-z,relro
 make[2]: Leaving directory '/build/reproducible-path/zopfli-1.0.3'
@@ -370,9 +406,9 @@
    dh_gencontrol
    dh_md5sums
    dh_builddeb
-dpkg-deb: building package 'zopfli' in '../zopfli_1.0.3-3_armhf.deb'.
-dpkg-deb: building package 'libzopfli1' in '../libzopfli1_1.0.3-3_armhf.deb'.
 dpkg-deb: building package 'libzopfli-dev' in '../libzopfli-dev_1.0.3-3_armhf.deb'.
+dpkg-deb: building package 'libzopfli1' in '../libzopfli1_1.0.3-3_armhf.deb'.
+dpkg-deb: building package 'zopfli' in '../zopfli_1.0.3-3_armhf.deb'.
 dpkg-deb: building package 'zopfli-dbgsym' in '../zopfli-dbgsym_1.0.3-3_armhf.deb'.
 dpkg-deb: building package 'libzopfli1-dbgsym' in '../libzopfli1-dbgsym_1.0.3-3_armhf.deb'.
  dpkg-genbuildinfo --build=binary -O../zopfli_1.0.3-3_armhf.buildinfo
@@ -382,12 +418,14 @@
 dpkg-buildpackage: info: binary-only upload (no source included)
 dpkg-genchanges: info: not including original source code in upload
 I: copying local configuration
+I: user script /srv/workspace/pbuilder/21463/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/21463/tmp/hooks/B01_cleanup finished
 I: unmounting dev/ptmx filesystem
 I: unmounting dev/pts filesystem
 I: unmounting dev/shm filesystem
 I: unmounting proc filesystem
 I: unmounting sys filesystem
 I: cleaning the build env 
-I: removing directory /srv/workspace/pbuilder/8738 and its subdirectories
-I: Current time: Mon Jan 27 22:44:07 -12 2025
-I: pbuilder-time-stamp: 1738061047
+I: removing directory /srv/workspace/pbuilder/21463 and its subdirectories
+I: Current time: Wed Jan 29 00:46:19 +14 2025
+I: pbuilder-time-stamp: 1738061179