Diff of the two buildlogs:

--
--- b1/build.log	2024-12-24 22:00:59.027627544 +0000
+++ b2/build.log	2024-12-24 22:05:35.883069862 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Tue Dec 24 09:56:35 -12 2024
-I: pbuilder-time-stamp: 1735077395
+I: Current time: Tue Jan 27 18:24:02 +14 2026
+I: pbuilder-time-stamp: 1769487842
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/trixie-reproducible-base.tgz]
 I: copying local configuration
@@ -26,51 +26,83 @@
 dpkg-source: info: unpacking gap-io_4.9.1+ds-1.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/767369/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/387852/tmp/hooks/D01_modify_environment starting
+debug: Running on infom02-amd64.
+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 27 04:24 /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/387852/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/387852/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='amd64'
-  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]="x86_64-pc-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=amd64
+  DEBIAN_FRONTEND=noninteractive
   DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=12 '
-  DISTRIBUTION='trixie'
-  HOME='/root'
-  HOST_ARCH='amd64'
+  DIRSTACK=()
+  DISTRIBUTION=trixie
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=x86_64
+  HOST_ARCH=amd64
   IFS=' 	
   '
-  INVOCATION_ID='67f03afe95f84028a06bbce4c4a784cf'
-  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='767369'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=38a6e15caa7248eeb24ef099f85f6859
+  LANG=C
+  LANGUAGE=et_EE:et
+  LC_ALL=C
+  MACHTYPE=x86_64-pc-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=387852
   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.DDhKQpnA/pbuilderrc_juXv --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.DDhKQpnA/b1 --logfile b1/build.log gap-io_4.9.1+ds-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'
+  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.DDhKQpnA/pbuilderrc_A2m1 --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.DDhKQpnA/b2 --logfile b2/build.log gap-io_4.9.1+ds-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'
 I: uname -a
-  Linux infom01-amd64 6.1.0-28-cloud-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.119-1 (2024-11-22) x86_64 GNU/Linux
+  Linux i-capture-the-hostname 6.11.10+bpo-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.11.10-1~bpo12+1 (2024-12-19) x86_64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Nov 22 14:40 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/767369/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Nov 22  2024 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/387852/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -243,7 +275,7 @@
 Get: 119 http://deb.debian.org/debian trixie/main amd64 texlive-latex-recommended all 2024.20241115-1 [8757 kB]
 Get: 120 http://deb.debian.org/debian trixie/main amd64 texlive-pictures all 2024.20241115-1 [17.0 MB]
 Get: 121 http://deb.debian.org/debian trixie/main amd64 texlive-latex-extra all 2024.20241115-1 [24.6 MB]
-Fetched 151 MB in 2s (63.4 MB/s)
+Fetched 151 MB in 3s (54.2 MB/s)
 debconf: delaying package configuration, since apt-utils is not installed
 Selecting previously unselected package libpython3.12-minimal:amd64.
 (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 ... 19966 files and directories currently installed.)
@@ -654,8 +686,8 @@
 Setting up tzdata (2024b-4) ...
 
 Current default time zone: 'Etc/UTC'
-Local time is now:      Tue Dec 24 21:58:57 UTC 2024.
-Universal Time is now:  Tue Dec 24 21:58:57 UTC 2024.
+Local time is now:      Tue Jan 27 04:26:15 UTC 2026.
+Universal Time is now:  Tue Jan 27 04:26:15 UTC 2026.
 Run 'dpkg-reconfigure tzdata' if you wish to change it.
 
 Setting up gap-autodoc (2023.06.19-1) ...
@@ -774,7 +806,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/gap-io-4.9.1+ds/ && 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  > ../gap-io_4.9.1+ds-1_source.changes
+I: user script /srv/workspace/pbuilder/387852/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/387852/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/gap-io-4.9.1+ds/ && 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  > ../gap-io_4.9.1+ds-1_source.changes
 dpkg-buildpackage: info: source package gap-io
 dpkg-buildpackage: info: source version 4.9.1+ds-1
 dpkg-buildpackage: info: source distribution unstable
@@ -972,23 +1008,23 @@
 Architecture: x86_64-pc-linux-gnu-default64-kv9
 
 testing: ./_build/tst/all.tst
-       1 ms (0 ms GC) and 222KB allocated for all.tst
+       2 ms (0 ms GC) and 222KB allocated for all.tst
 testing: ./_build/tst/bugfix.tst
-     134 ms (16 ms GC) and 24.1MB allocated for bugfix.tst
+     163 ms (13 ms GC) and 24.1MB allocated for bugfix.tst
 testing: ./_build/tst/children.tst
        0 ms (0 ms GC) and 41.8KB allocated for children.tst
 testing: ./_build/tst/funcs.tst
        1 ms (0 ms GC) and 106KB allocated for funcs.tst
 testing: ./_build/tst/sendstringbackground.tst
-       9 ms (0 ms GC) and 33.7KB allocated for sendstringbackground.tst
+       3 ms (0 ms GC) and 33.7KB allocated for sendstringbackground.tst
 testing: ./_build/tst/testgap.tst
-    2026 ms (158 ms GC) and 680MB allocated for testgap.tst
+    3072 ms (184 ms GC) and 677MB allocated for testgap.tst
 testing: ./_build/tst/timeout.tst
-      45 ms (44 ms GC) and 117KB allocated for timeout.tst
+      55 ms (49 ms GC) and 116KB allocated for timeout.tst
 testing: ./_build/tst/waitpid.tst
-      33 ms (33 ms GC) and 55.2KB allocated for waitpid.tst
+      31 ms (30 ms GC) and 55.2KB allocated for waitpid.tst
 -----------------------------------
-total      2249 ms (251 ms GC) and 705MB allocated
+total      3327 ms (276 ms GC) and 702MB allocated
               0 failures in 8 files
 
 #I  No errors detected while testing
@@ -1032,8 +1068,8 @@
 make[1]: Leaving directory '/build/reproducible-path/gap-io-4.9.1+ds'
    dh_md5sums
    dh_builddeb
-dpkg-deb: building package 'gap-io' in '../gap-io_4.9.1+ds-1_amd64.deb'.
 dpkg-deb: building package 'gap-io-dbgsym' in '../gap-io-dbgsym_4.9.1+ds-1_amd64.deb'.
+dpkg-deb: building package 'gap-io' in '../gap-io_4.9.1+ds-1_amd64.deb'.
  dpkg-genbuildinfo --build=binary -O../gap-io_4.9.1+ds-1_amd64.buildinfo
  dpkg-genchanges --build=binary -O../gap-io_4.9.1+ds-1_amd64.changes
 dpkg-genchanges: info: binary-only upload (no source code included)
@@ -1041,39 +1077,41 @@
 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/387852/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/387852/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
 W: Stray processes left from build:
-* system-pbuilder-build-gap\x2dio_4.9.1\x2bds\x2d1-767369.slice - Slice /system/pbuilder/build/gap-io_4.9.1+ds-1/767369
+* system-pbuilder-build-gap\x2dio_4.9.1\x2bds\x2d1-387852.slice - Slice /system/pbuilder/build/gap-io_4.9.1+ds-1/387852
      Loaded: loaded
-     Active: active since Tue 2024-12-24 09:56:44 -12; 4min 8s ago
+     Active: active since Tue 2026-01-27 18:24:09 +14; 4min 20s ago
       Tasks: 16
-     Memory: 797.4M
-        CPU: 1min 33.528s
-     CGroup: /system.slice/system-pbuilder.slice/system-pbuilder-build.slice/system-pbuilder-build-gap\x2dio_4.9.1\x2bds\x2d1.slice/system-pbuilder-build-gap\x2dio_4.9.1\x2bds\x2d1-767369.slice
-             `-run-r1de2b4b881654ec1b8c9c5425c831982.scope
-               |-802622 /bin/bash ./tst/sleep.sh 3600
-               |-802623 /bin/bash ./tst/sleep.sh 3600
-               |-802624 /bin/bash ./tst/sleep.sh 3600
-               |-802625 sleep 3600
-               |-802626 sleep 3600
-               |-802627 /bin/bash ./tst/sleep.sh 3600
-               |-802629 /bin/bash ./tst/sleep.sh 3600
-               |-802630 sleep 3600
-               |-802631 /bin/bash ./tst/sleep.sh 3600
-               |-802632 /bin/bash ./tst/sleep.sh 3600
-               |-802633 sleep 3600
-               |-802636 /bin/bash ./tst/sleep.sh 3600
-               |-802637 sleep 3600
-               |-802639 sleep 3600
-               |-802640 sleep 3600
-               `-802641 sleep 3600
+     Memory: 948.4M
+        CPU: 2min 88ms
+     CGroup: /system.slice/system-pbuilder.slice/system-pbuilder-build.slice/system-pbuilder-build-gap\x2dio_4.9.1\x2bds\x2d1.slice/system-pbuilder-build-gap\x2dio_4.9.1\x2bds\x2d1-387852.slice
+             `-run-r5b5c53223ea34d42b0cc65d05b5c3d64.scope
+               |-409615 /bin/bash ./tst/sleep.sh 3600
+               |-409616 /bin/bash ./tst/sleep.sh 3600
+               |-409617 sleep 3600
+               |-409618 /bin/bash ./tst/sleep.sh 3600
+               |-409619 sleep 3600
+               |-409620 /bin/bash ./tst/sleep.sh 3600
+               |-409621 sleep 3600
+               |-409622 /bin/bash ./tst/sleep.sh 3600
+               |-409623 sleep 3600
+               |-409624 /bin/bash ./tst/sleep.sh 3600
+               |-409625 sleep 3600
+               |-409626 /bin/bash ./tst/sleep.sh 3600
+               |-409627 sleep 3600
+               |-409628 /bin/bash ./tst/sleep.sh 3600
+               |-409629 sleep 3600
+               `-409630 sleep 3600
 
-Dec 24 09:56:44 infom01-amd64 systemd[1]: Created slice system-pbuilder-build-gap\x2dio_4.9.1\x2bds\x2d1-767369.slice - Slice /system/pbuilder/build/gap-io_4.9.1+ds-1/767369.
+Jan 27 18:24:09 infom02-amd64 systemd[1]: Created slice system-pbuilder-build-gap\x2dio_4.9.1\x2bds\x2d1-387852.slice - Slice /system/pbuilder/build/gap-io_4.9.1+ds-1/387852.
 I: cleaning the build env 
-I: removing directory /srv/workspace/pbuilder/767369 and its subdirectories
-I: Current time: Tue Dec 24 10:00:58 -12 2024
-I: pbuilder-time-stamp: 1735077658
+I: removing directory /srv/workspace/pbuilder/387852 and its subdirectories
+I: Current time: Tue Jan 27 18:28:35 +14 2026
+I: pbuilder-time-stamp: 1769488115