Diff of the two buildlogs:

--
--- b1/build.log	2023-05-22 07:28:55.854933842 +0000
+++ b2/build.log	2023-05-22 07:32:34.893406607 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sun May 21 19:25:15 -12 2023
-I: pbuilder-time-stamp: 1684740315
+I: Current time: Mon Jun 24 03:51:59 +14 2024
+I: pbuilder-time-stamp: 1719150719
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/bookworm-reproducible-base.tgz]
 I: copying local configuration
@@ -16,7 +16,7 @@
 I: copying [./jam-lib_0.1.git20180106.740247a+dfsg.orig.tar.xz]
 I: copying [./jam-lib_0.1.git20180106.740247a+dfsg-1.debian.tar.xz]
 I: Extracting source
-gpgv: Signature made Tue Jan  8 01:01:01 2019 -12
+gpgv: Signature made Wed Jan  9 03:01:01 2019 +14
 gpgv:                using RSA key F1F007320A035541F0A663CA578A0494D1C646D1
 gpgv:                issuer "tille@debian.org"
 gpgv: Can't check signature: No public key
@@ -29,52 +29,84 @@
 dpkg-source: info: applying javadoc.patch
 I: using fakeroot in build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/19451/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/22936/tmp/hooks/D01_modify_environment starting
+debug: Running on codethink13-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 Jun 24 03:52 /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/22936/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/22936/tmp/hooks/D02_print_environment starting
 I: set
-  BUILDDIR='/build'
-  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]="15" [3]="1" [4]="release" [5]="aarch64-unknown-linux-gnu")
+  BASH_VERSION='5.2.15(1)-release'
+  BUILDDIR=/build
+  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=8 '
-  DISTRIBUTION='bookworm'
-  HOME='/var/lib/jenkins'
-  HOST_ARCH='arm64'
+  DIRSTACK=()
+  DISTRIBUTION=bookworm
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/var/lib/jenkins
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=aarch64
+  HOST_ARCH=arm64
   IFS=' 	
   '
-  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='19451'
-  PS1='# '
-  PS2='> '
+  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=22936
   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.eraUOFKv/pbuilderrc_6qiv --distribution bookworm --hookdir /etc/pbuilder/first-build-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/bookworm-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.eraUOFKv/b1 --logfile b1/build.log jam-lib_0.1.git20180106.740247a+dfsg-1.dsc'
-  SUDO_GID='117'
-  SUDO_UID='110'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  USERNAME='root'
-  _='/usr/bin/systemd-run'
-  http_proxy='http://192.168.101.16:3128'
+  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.eraUOFKv/pbuilderrc_W2E2 --distribution bookworm --hookdir /etc/pbuilder/rebuild-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/bookworm-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.eraUOFKv/b2 --logfile b2/build.log --extrapackages usrmerge jam-lib_0.1.git20180106.740247a+dfsg-1.dsc'
+  SUDO_GID=117
+  SUDO_UID=110
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  USERNAME=root
+  _='I: set'
+  http_proxy=http://192.168.101.16:3128
 I: uname -a
-  Linux codethink12-arm64 4.15.0-211-generic #222-Ubuntu SMP Tue Apr 18 18:58:27 UTC 2023 aarch64 GNU/Linux
+  Linux i-capture-the-hostname 4.15.0-211-generic #222-Ubuntu SMP Tue Apr 18 18:58:27 UTC 2023 aarch64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 May 20 22:26 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/19451/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Jun 22 06:49 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/22936/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -338,7 +370,7 @@
 Get: 214 http://deb.debian.org/debian bookworm/main arm64 javahelper all 0.78 [97.2 kB]
 Get: 215 http://deb.debian.org/debian bookworm/main arm64 libtrove-java all 2.1.0-3 [709 kB]
 Get: 216 http://deb.debian.org/debian bookworm/main arm64 libtrove-java-doc all 2.1.0-3 [530 kB]
-Fetched 379 MB in 44s (8627 kB/s)
+Fetched 379 MB in 38s (9899 kB/s)
 debconf: delaying package configuration, since apt-utils is not installed
 Selecting previously unselected package libpython3.11-minimal:arm64.
 (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 ... 19616 files and directories currently installed.)
@@ -1405,10 +1437,15 @@
 Reading package lists...
 Building dependency tree...
 Reading state information...
+usrmerge is already the newest version (35).
 fakeroot is already the newest version (1.31-1.2).
 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
 I: Building the package
-I: Running cd /build/jam-lib-0.1.git20180106.740247a+dfsg/ && 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  > ../jam-lib_0.1.git20180106.740247a+dfsg-1_source.changes
+I: user script /srv/workspace/pbuilder/22936/tmp/hooks/A99_set_merged_usr starting
+Re-configuring usrmerge...
+I: user script /srv/workspace/pbuilder/22936/tmp/hooks/A99_set_merged_usr finished
+hostname: Temporary failure in name resolution
+I: Running cd /build/jam-lib-0.1.git20180106.740247a+dfsg/ && 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  > ../jam-lib_0.1.git20180106.740247a+dfsg-1_source.changes
 dpkg-buildpackage: info: source package jam-lib
 dpkg-buildpackage: info: source version 0.1.git20180106.740247a+dfsg-1
 dpkg-buildpackage: info: source distribution unstable
@@ -1561,7 +1598,7 @@
       [jar] Building jar: /build/jam-lib-0.1.git20180106.740247a+dfsg/dist/jam.jar
 
 BUILD SUCCESSFUL
-Total time: 21 seconds
+Total time: 20 seconds
 ant -buildfile javadoc.xml
 Buildfile: /build/jam-lib-0.1.git20180106.740247a+dfsg/javadoc.xml
 
@@ -1812,7 +1849,7 @@
   [javadoc] 1 error
 
 BUILD SUCCESSFUL
-Total time: 27 seconds
+Total time: 25 seconds
 make[1]: Leaving directory '/build/jam-lib-0.1.git20180106.740247a+dfsg'
    dh_auto_test
    create-stamp debian/debhelper-build-stamp
@@ -1847,12 +1884,14 @@
 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/22936/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/22936/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/19451 and its subdirectories
-I: Current time: Sun May 21 19:28:54 -12 2023
-I: pbuilder-time-stamp: 1684740534
+I: removing directory /srv/workspace/pbuilder/22936 and its subdirectories
+I: Current time: Mon Jun 24 03:55:33 +14 2024
+I: pbuilder-time-stamp: 1719150933