Diff of the two buildlogs:

--
--- b1/build.log	2024-06-05 21:53:28.154230025 +0000
+++ b2/build.log	2024-06-05 21:55:18.673526297 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Wed Jun  5 09:50:05 -12 2024
-I: pbuilder-time-stamp: 1717624205
+I: Current time: Thu Jun  6 11:53:38 +14 2024
+I: pbuilder-time-stamp: 1717624418
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/trixie-reproducible-base.tgz]
 I: copying local configuration
@@ -26,52 +26,84 @@
 dpkg-source: info: unpacking ocaml-integers_0.7.0-3.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/32148/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/1887/tmp/hooks/D01_modify_environment starting
+debug: Running on virt64z.
+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  5 21:53 /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/1887/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/1887/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]="21" [3]="1" [4]="release" [5]="arm-unknown-linux-gnueabihf")
+  BASH_VERSION='5.2.21(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='ecd09ac19c824f619f0e5b0dc62a8008'
-  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='32148'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=8fbfa7a6235e400bb126943fca24f49a
+  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=1887
   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.WvmBVqVV/pbuilderrc_Gmj9 --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.WvmBVqVV/b1 --logfile b1/build.log ocaml-integers_0.7.0-3.dsc'
-  SUDO_GID='113'
-  SUDO_UID='107'
-  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.WvmBVqVV/pbuilderrc_2hfQ --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.WvmBVqVV/b2 --logfile b2/build.log ocaml-integers_0.7.0-3.dsc'
+  SUDO_GID=110
+  SUDO_UID=103
+  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 cbxi4a 6.1.0-21-armmp #1 SMP Debian 6.1.90-1 (2024-05-03) armv7l GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-21-arm64 #1 SMP Debian 6.1.90-1 (2024-05-03) aarch64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Jun  3 11:28 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/32148/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Jun  5 11:24 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/1887/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -152,7 +184,7 @@
 Get: 37 http://deb.debian.org/debian trixie/main armhf ocaml-interp armhf 4.14.1-1 [6458 kB]
 Get: 38 http://deb.debian.org/debian trixie/main armhf ocaml armhf 4.14.1-1 [66.5 MB]
 Get: 39 http://deb.debian.org/debian trixie/main armhf ocaml-dune armhf 3.14.0-1 [4314 kB]
-Fetched 136 MB in 10s (14.1 MB/s)
+Fetched 136 MB in 3s (42.6 MB/s)
 debconf: delaying package configuration, since apt-utils is not installed
 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 ... 19443 files and directories currently installed.)
@@ -323,7 +355,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/ocaml-integers-0.7.0/ && 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  > ../ocaml-integers_0.7.0-3_source.changes
+I: user script /srv/workspace/pbuilder/1887/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/1887/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/ocaml-integers-0.7.0/ && 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  > ../ocaml-integers_0.7.0-3_source.changes
 dpkg-buildpackage: info: source package ocaml-integers
 dpkg-buildpackage: info: source version 0.7.0-3
 dpkg-buildpackage: info: source distribution unstable
@@ -344,18 +380,18 @@
    dh_ocamlinit -O--buildsystem=ocaml_dune
    dh_auto_configure -O--buildsystem=ocaml_dune
    dh_auto_build -O--buildsystem=ocaml_dune
-	dune build -j 3 -p integers
+	dune build -j 4 -p integers
    dh_auto_test -O--buildsystem=ocaml_dune
-	dune runtest -j 3 -p integers
-(cd _build/default/test && ./hexprinting.exe)
-Hexstring test: ?
-Hexstring test: ✓
+	dune runtest -j 4 -p integers
 (cd _build/default/test && ./uint32conversions.exe)
 UInt32-Int32 conversion test: ?
 UInt32-Int32 conversion test: ✓
 (cd _build/default/test && ./uint64conversions.exe)
 UInt64-Int64 conversion test: ?
 UInt64-Int64 conversion test: ✓
+(cd _build/default/test && ./hexprinting.exe)
+Hexstring test: ?
+Hexstring test: ✓
    create-stamp debian/debhelper-build-stamp
    dh_testroot -O--buildsystem=ocaml_dune
    dh_prep -O--buildsystem=ocaml_dune
@@ -383,8 +419,8 @@
    dh_md5sums -O--buildsystem=ocaml_dune
    dh_builddeb -O--buildsystem=ocaml_dune
 dpkg-deb: building package 'libintegers-ocaml-dev' in '../libintegers-ocaml-dev_0.7.0-3_armhf.deb'.
-dpkg-deb: building package 'libintegers-ocaml' in '../libintegers-ocaml_0.7.0-3_armhf.deb'.
 dpkg-deb: building package 'libintegers-ocaml-dbgsym' in '../libintegers-ocaml-dbgsym_0.7.0-3_armhf.deb'.
+dpkg-deb: building package 'libintegers-ocaml' in '../libintegers-ocaml_0.7.0-3_armhf.deb'.
  dpkg-genbuildinfo --build=binary -O../ocaml-integers_0.7.0-3_armhf.buildinfo
  dpkg-genchanges --build=binary -O../ocaml-integers_0.7.0-3_armhf.changes
 dpkg-genchanges: info: binary-only upload (no source code included)
@@ -392,12 +428,14 @@
 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/1887/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/1887/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/32148 and its subdirectories
-I: Current time: Wed Jun  5 09:53:23 -12 2024
-I: pbuilder-time-stamp: 1717624404
+I: removing directory /srv/workspace/pbuilder/1887 and its subdirectories
+I: Current time: Thu Jun  6 11:55:15 +14 2024
+I: pbuilder-time-stamp: 1717624515