Diff of the two buildlogs:

--
--- b1/build.log	2025-01-14 05:13:04.046900145 +0000
+++ b2/build.log	2025-01-14 05:16:59.980139158 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sun Feb 15 23:33:12 -12 2026
-I: pbuilder-time-stamp: 1771241592
+I: Current time: Tue Jan 14 19:13:07 +14 2025
+I: pbuilder-time-stamp: 1736831587
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/trixie-reproducible-base.tgz]
 I: copying local configuration
@@ -25,52 +25,84 @@
 dpkg-source: info: applying font-sizes.diff
 I: using fakeroot in build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/4138193/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/1691596/tmp/hooks/D01_modify_environment starting
+debug: Running on codethink04-arm64.
+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 14 05:13 /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/1691596/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/1691596/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='arm64'
-  DEBIAN_FRONTEND='noninteractive'
+  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]="aarch64-unknown-linux-gnu")
+  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=arm64
+  DEBIAN_FRONTEND=noninteractive
   DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=12 '
-  DISTRIBUTION='trixie'
-  HOME='/root'
-  HOST_ARCH='arm64'
+  DIRSTACK=()
+  DISTRIBUTION=trixie
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=aarch64
+  HOST_ARCH=arm64
   IFS=' 	
   '
-  INVOCATION_ID='56e20cdb1ba14d42b2ebc3d4fdee2335'
-  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='4138193'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=e95660cefff84566988e3ef47b711d18
+  LANG=C
+  LANGUAGE=nl_BE:nl
+  LC_ALL=C
+  MACHTYPE=aarch64-unknown-linux-gnu
+  MAIL=/var/mail/root
+  OPTERR=1
+  OPTIND=1
+  OSTYPE=linux-gnu
+  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=1691596
   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.gbmAfsLg/pbuilderrc_jZNG --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.gbmAfsLg/b1 --logfile b1/build.log tk8.6_8.6.16-1.dsc'
-  SUDO_GID='109'
-  SUDO_UID='104'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  _='/usr/bin/systemd-run'
-  http_proxy='http://192.168.101.4:3128'
+  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.gbmAfsLg/pbuilderrc_ApZH --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.gbmAfsLg/b2 --logfile b2/build.log tk8.6_8.6.16-1.dsc'
+  SUDO_GID=109
+  SUDO_UID=104
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  _='I: set'
+  http_proxy=http://192.168.101.4:3128
 I: uname -a
-  Linux codethink01-arm64 6.1.0-29-cloud-arm64 #1 SMP Debian 6.1.123-1 (2025-01-02) aarch64 GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-29-cloud-arm64 #1 SMP Debian 6.1.123-1 (2025-01-02) aarch64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Nov 22  2024 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/4138193/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Nov 22 14:40 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/1691596/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -194,7 +226,7 @@
 Get: 74 http://deb.debian.org/debian trixie/main arm64 libxss-dev arm64 1:1.2.3-1+b3 [22.8 kB]
 Get: 75 http://deb.debian.org/debian trixie/main arm64 tcl8.6 arm64 8.6.16+dfsg-1 [121 kB]
 Get: 76 http://deb.debian.org/debian trixie/main arm64 tcl8.6-dev arm64 8.6.16+dfsg-1 [1012 kB]
-Fetched 32.3 MB in 0s (108 MB/s)
+Fetched 32.3 MB in 0s (78.1 MB/s)
 Preconfiguring packages ...
 Selecting previously unselected package tzdata.
 (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 ... 19968 files and directories currently installed.)
@@ -447,8 +479,8 @@
 Setting up tzdata (2024b-4) ...
 
 Current default time zone: 'Etc/UTC'
-Local time is now:      Mon Feb 16 11:33:29 UTC 2026.
-Universal Time is now:  Mon Feb 16 11:33:29 UTC 2026.
+Local time is now:      Tue Jan 14 05:13:32 UTC 2025.
+Universal Time is now:  Tue Jan 14 05:13:32 UTC 2025.
 Run 'dpkg-reconfigure tzdata' if you wish to change it.
 
 Setting up xtrans-dev (1.4.0-1) ...
@@ -526,7 +558,11 @@
 fakeroot is already the newest version (1.36.2-1).
 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
 I: Building the package
-I: Running cd /build/reproducible-path/tk8.6-8.6.16/ && 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  > ../tk8.6_8.6.16-1_source.changes
+I: user script /srv/workspace/pbuilder/1691596/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/1691596/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/tk8.6-8.6.16/ && 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  > ../tk8.6_8.6.16-1_source.changes
 dpkg-buildpackage: info: source package tk8.6
 dpkg-buildpackage: info: source version 8.6.16-1
 dpkg-buildpackage: info: source distribution unstable
@@ -896,7 +932,6 @@
         rm $f ; \
      fi ; \
   done
-libfakeroot internal error: payload not recognized!
 make[1]: Leaving directory '/build/reproducible-path/tk8.6-8.6.16'
    dh_install
    dh_installdocs
@@ -930,12 +965,12 @@
    dh_gencontrol
    dh_md5sums
    dh_builddeb
-dpkg-deb: building package 'tk8.6-dev' in '../tk8.6-dev_8.6.16-1_arm64.deb'.
-dpkg-deb: building package 'tk8.6-dbgsym' in '../tk8.6-dbgsym_8.6.16-1_arm64.deb'.
 dpkg-deb: building package 'tk8.6' in '../tk8.6_8.6.16-1_arm64.deb'.
-dpkg-deb: building package 'libtk8.6-dbgsym' in '../libtk8.6-dbgsym_8.6.16-1_arm64.deb'.
+dpkg-deb: building package 'tk8.6-dbgsym' in '../tk8.6-dbgsym_8.6.16-1_arm64.deb'.
 dpkg-deb: building package 'libtk8.6' in '../libtk8.6_8.6.16-1_arm64.deb'.
+dpkg-deb: building package 'libtk8.6-dbgsym' in '../libtk8.6-dbgsym_8.6.16-1_arm64.deb'.
 dpkg-deb: building package 'tk8.6-doc' in '../tk8.6-doc_8.6.16-1_all.deb'.
+dpkg-deb: building package 'tk8.6-dev' in '../tk8.6-dev_8.6.16-1_arm64.deb'.
  dpkg-genbuildinfo --build=binary -O../tk8.6_8.6.16-1_arm64.buildinfo
  dpkg-genchanges --build=binary -O../tk8.6_8.6.16-1_arm64.changes
 dpkg-genchanges: info: binary-only upload (no source code included)
@@ -943,12 +978,14 @@
 dpkg-buildpackage: info: binary-only upload (no source included)
 dpkg-genchanges: info: including full source code in upload
 I: copying local configuration
+I: user script /srv/workspace/pbuilder/1691596/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/1691596/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/4138193 and its subdirectories
-I: Current time: Sun Feb 15 23:36:02 -12 2026
-I: pbuilder-time-stamp: 1771241762
+I: removing directory /srv/workspace/pbuilder/1691596 and its subdirectories
+I: Current time: Tue Jan 14 19:16:58 +14 2025
+I: pbuilder-time-stamp: 1736831818