Diff of the two buildlogs:

--
--- b1/build.log	2025-01-20 18:28:41.831759411 +0000
+++ b2/build.log	2025-01-20 18:29:57.700347537 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Mon Jan 20 06:27:01 -12 2025
-I: pbuilder-time-stamp: 1737397621
+I: Current time: Mon Feb 23 14:51:44 +14 2026
+I: pbuilder-time-stamp: 1771807904
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/unstable-reproducible-base.tgz]
 I: copying local configuration
@@ -22,52 +22,84 @@
 dpkg-source: info: unpacking ocaml-qcheck_0.23-1.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/2160155/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/484890/tmp/hooks/D01_modify_environment starting
+debug: Running on codethink01-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 Feb 23 00:51 /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/484890/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/484890/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='unstable'
-  HOME='/root'
-  HOST_ARCH='arm64'
+  DIRSTACK=()
+  DISTRIBUTION=unstable
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=aarch64
+  HOST_ARCH=arm64
   IFS=' 	
   '
-  INVOCATION_ID='d4e049b3458446b185bed5b5436f3e9c'
-  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='2160155'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=1f6c32f22321426b91b8296367b496d9
+  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=484890
   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.P1Sqga4j/pbuilderrc_2udx --distribution unstable --hookdir /etc/pbuilder/first-build-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/unstable-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.P1Sqga4j/b1 --logfile b1/build.log ocaml-qcheck_0.23-1.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.P1Sqga4j/pbuilderrc_H6Y6 --distribution unstable --hookdir /etc/pbuilder/rebuild-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/unstable-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.P1Sqga4j/b2 --logfile b2/build.log ocaml-qcheck_0.23-1.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 codethink02-arm64 6.1.0-30-cloud-arm64 #1 SMP Debian 6.1.124-1 (2025-01-12) aarch64 GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-30-cloud-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/2160155/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Nov 22  2024 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/484890/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -173,7 +205,7 @@
 Get: 54 http://deb.debian.org/debian unstable/main arm64 ocaml-dune arm64 3.17.1-2 [5578 kB]
 Get: 55 http://deb.debian.org/debian unstable/main arm64 ocaml-findlib arm64 1.9.6-3 [621 kB]
 Get: 56 http://deb.debian.org/debian unstable/main arm64 ocaml-odoc arm64 2.4.4-2 [4940 kB]
-Fetched 125 MB in 1s (109 MB/s)
+Fetched 125 MB in 1s (136 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 ... 19965 files and directories currently installed.)
@@ -412,7 +444,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/ocaml-qcheck-0.23/ && 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-qcheck_0.23-1_source.changes
+I: user script /srv/workspace/pbuilder/484890/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for unstable
+I: user script /srv/workspace/pbuilder/484890/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/ocaml-qcheck-0.23/ && 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-qcheck_0.23-1_source.changes
 dpkg-buildpackage: info: source package ocaml-qcheck
 dpkg-buildpackage: info: source version 0.23-1
 dpkg-buildpackage: info: source distribution unstable
@@ -439,16 +475,13 @@
 dune build -p "qcheck,qcheck-core,qcheck-ounit,qcheck-alcotest" @doc
 Warning: Cache directories could not be created: Permission denied; disabling
 cache
-Hint: Make sure the directory /nonexistent/first-build/.cache/dune/db/temp
+Hint: Make sure the directory /nonexistent/second-build/.cache/dune/db/temp
 can be created
 (cd _build/default/_doc/_odoc/pkg/qcheck-core && /usr/bin/odoc compile --pkg qcheck-core -o page-index.odoc ../../../../doc/index.mld)
 File "../../../../doc/index.mld", line 8, characters 0-3:
 Warning: Heading label should not be empty.
 File "../../../../doc/index.mld", line 24, characters 0-3:
 Warning: Heading label should not be empty.
-(cd _build/default/_doc/_html && /usr/bin/odoc link -I ../_odoc/pkg/qcheck-core -I ../../src/core/.qcheck_core.objs/byte -I ../../src/runner/.qcheck_runner.objs/byte -o ../_odocls/qcheck-core/qCheck_base_runner.odocl ../../src/runner/.qcheck_runner.objs/byte/qCheck_base_runner.odoc)
-File "src/runner/QCheck_base_runner.mli", line 28, characters 42-48:
-Warning: Failed to resolve reference unresolvedroot(Arg) Couldn't find "Arg"
 (cd _build/default/_doc/_html && /usr/bin/odoc link -I ../_odoc/pkg/qcheck-core -I ../../src/core/.qcheck_core.objs/byte -I ../../src/runner/.qcheck_runner.objs/byte -o ../_odocls/qcheck-core/qCheck.odocl ../../src/core/.qcheck_core.objs/byte/qCheck.odoc)
 File "src/core/QCheck.mli", line 1769, characters 17-26:
 Warning: While resolving the expansion of include at File "src/core/QCheck.mli", line 1772, character 2
@@ -495,6 +528,9 @@
 Warning: Failed to resolve reference unresolvedroot(Invalid_argument) Couldn't find "Invalid_argument"
 File "src/core/QCheck.mli", line 81, characters 4-16:
 Warning: Failed to resolve reference unresolvedroot(Generator) Couldn't find "Generator"
+(cd _build/default/_doc/_html && /usr/bin/odoc link -I ../_odoc/pkg/qcheck-core -I ../../src/core/.qcheck_core.objs/byte -I ../../src/runner/.qcheck_runner.objs/byte -o ../_odocls/qcheck-core/qCheck_base_runner.odocl ../../src/runner/.qcheck_runner.objs/byte/qCheck_base_runner.odoc)
+File "src/runner/QCheck_base_runner.mli", line 28, characters 42-48:
+Warning: Failed to resolve reference unresolvedroot(Arg) Couldn't find "Arg"
 (cd _build/default/_doc/_html && /usr/bin/odoc link -I ../_odoc/pkg/qcheck-core -I ../../src/core/.qcheck_core.objs/byte -I ../../src/runner/.qcheck_runner.objs/byte -o ../_odocls/qcheck-core/qCheck2.odocl ../../src/core/.qcheck_core.objs/byte/qCheck2.odoc)
 File "src/core/QCheck2.mli", line 1981, characters 61-67:
 Warning: Failed to resolve reference unresolvedroot(map) Couldn't find "map"
@@ -579,7 +615,7 @@
 	dune runtest -j 12 -p qcheck,qcheck-core,qcheck-ounit,qcheck-alcotest
 (cd _build/default/test/core && ./QCheck2_unit_tests.exe)
 Testing `QCheck2'.
-This run has ID `TERID07W'.
+This run has ID `TVKDMN43'.
 
   [OK]          Shrink                          0   int_towards.
   [OK]          Shrink                          1   int32_towards.
@@ -610,10 +646,10 @@
   [OK]          Test.check_exn                  6   check_exn Unexpected succ...
 
 Full test results in `/build/reproducible-path/ocaml-qcheck-0.23/_build/default/test/core/_build/_tests/QCheck2'.
-Test Successful in 0.013s. 27 tests run.
+Test Successful in 0.005s. 27 tests run.
 (cd _build/default/test/core && ./QCheck_unit_tests.exe)
 Testing `QCheck'.
-This run has ID `ETJIKD9D'.
+This run has ID `T9EODXM7'.
 
   [OK]          Shrink                          0   bool.
   [OK]          Shrink                          1   int.
@@ -645,7 +681,7 @@
   [OK]          Test.make ~long_factor          4   make with negative long_f...
 
 Full test results in `/build/reproducible-path/ocaml-qcheck-0.23/_build/default/test/core/_build/_tests/QCheck'.
-Test Successful in 0.012s. 28 tests run.
+Test Successful in 0.013s. 28 tests run.
 make[1]: Leaving directory '/build/reproducible-path/ocaml-qcheck-0.23'
    create-stamp debian/debhelper-build-stamp
    dh_testroot -O--buildsystem=ocaml_dune
@@ -665,37 +701,37 @@
    dh_fixperms -O--buildsystem=ocaml_dune
    dh_missing -O--buildsystem=ocaml_dune
    dh_dwz -a -O--buildsystem=ocaml_dune
+dwz: debian/libqcheck-ounit-ocaml/usr/lib/aarch64-linux-gnu/ocaml/5.2.0/qcheck-ounit/qcheck_ounit.cmxs: DWARF compression not beneficial - old size 2553 new size 2553
 dwz: debian/libqcheck-ocaml/usr/lib/aarch64-linux-gnu/ocaml/5.2.0/qcheck-alcotest/qcheck_alcotest.cmxs: DWARF compression not beneficial - old size 705 new size 705
 dwz: debian/libqcheck-ocaml/usr/lib/aarch64-linux-gnu/ocaml/5.2.0/qcheck/qcheck.cmxs: DWARF compression not beneficial - old size 188 new size 188
 dwz: debian/libqcheck-core-ocaml/usr/lib/aarch64-linux-gnu/ocaml/5.2.0/qcheck-core/runner/qcheck_runner.cmxs: DWARF compression not beneficial - old size 4857 new size 4857
-dwz: debian/libqcheck-ounit-ocaml/usr/lib/aarch64-linux-gnu/ocaml/5.2.0/qcheck-ounit/qcheck_ounit.cmxs: DWARF compression not beneficial - old size 2553 new size 2553
    dh_strip -a -O--buildsystem=ocaml_dune
    dh_makeshlibs -a -O--buildsystem=ocaml_dune
    dh_shlibdeps -a -O--buildsystem=ocaml_dune
    dh_installdeb -O--buildsystem=ocaml_dune
    dh_ocaml -O--buildsystem=ocaml_dune
    dh_gencontrol -O--buildsystem=ocaml_dune
-dpkg-gencontrol: warning: Depends field of package libqcheck-core-ocaml-dev: substitution variable ${shlibs:Depends} used, but is not defined
-dpkg-gencontrol: warning: Depends field of package libqcheck-ounit-ocaml: substitution variable ${shlibs:Depends} used, but is not defined
-dpkg-gencontrol: warning: Depends field of package libqcheck-core-ocaml: substitution variable ${shlibs:Depends} used, but is not defined
 dpkg-gencontrol: warning: Depends field of package libqcheck-ocaml: substitution variable ${shlibs:Depends} used, but is not defined
-dpkg-gencontrol: warning: Depends field of package libqcheck-ocaml-dev: substitution variable ${shlibs:Depends} used, but is not defined
 dpkg-gencontrol: warning: Depends field of package libqcheck-ounit-ocaml-dev: substitution variable ${shlibs:Depends} used, but is not defined
+dpkg-gencontrol: warning: Depends field of package libqcheck-ounit-ocaml: substitution variable ${shlibs:Depends} used, but is not defined
 dpkg-gencontrol: warning: Depends field of package libqcheck-core-ocaml: substitution variable ${shlibs:Depends} used, but is not defined
+dpkg-gencontrol: warning: Depends field of package libqcheck-core-ocaml-dev: substitution variable ${shlibs:Depends} used, but is not defined
+dpkg-gencontrol: warning: Depends field of package libqcheck-ocaml-dev: substitution variable ${shlibs:Depends} used, but is not defined
 dpkg-gencontrol: warning: Depends field of package libqcheck-ounit-ocaml: substitution variable ${shlibs:Depends} used, but is not defined
+dpkg-gencontrol: warning: Depends field of package libqcheck-core-ocaml: substitution variable ${shlibs:Depends} used, but is not defined
 dpkg-gencontrol: warning: Depends field of package libqcheck-ocaml: substitution variable ${shlibs:Depends} used, but is not defined
    dh_md5sums -O--buildsystem=ocaml_dune
    dh_builddeb -O--buildsystem=ocaml_dune
+dpkg-deb: building package 'libqcheck-ocaml-dbgsym' in '../libqcheck-ocaml-dbgsym_0.23-1_arm64.deb'.
+dpkg-deb: building package 'libqcheck-ocaml' in '../libqcheck-ocaml_0.23-1_arm64.deb'.
 dpkg-deb: building package 'libqcheck-ocaml-dev' in '../libqcheck-ocaml-dev_0.23-1_arm64.deb'.
-dpkg-deb: building package 'libqcheck-ocaml-doc' in '../libqcheck-ocaml-doc_0.23-1_all.deb'.
-dpkg-deb: building package 'libqcheck-ounit-ocaml-dev' in '../libqcheck-ounit-ocaml-dev_0.23-1_arm64.deb'.
+dpkg-deb: building package 'libqcheck-core-ocaml' in '../libqcheck-core-ocaml_0.23-1_arm64.deb'.
 dpkg-deb: building package 'libqcheck-ounit-ocaml-dbgsym' in '../libqcheck-ounit-ocaml-dbgsym_0.23-1_arm64.deb'.
+dpkg-deb: building package 'libqcheck-core-ocaml-dbgsym' in '../libqcheck-core-ocaml-dbgsym_0.23-1_arm64.deb'.
 dpkg-deb: building package 'libqcheck-core-ocaml-dev' in '../libqcheck-core-ocaml-dev_0.23-1_arm64.deb'.
-dpkg-deb: building package 'libqcheck-core-ocaml' in '../libqcheck-core-ocaml_0.23-1_arm64.deb'.
-dpkg-deb: building package 'libqcheck-ocaml' in '../libqcheck-ocaml_0.23-1_arm64.deb'.
 dpkg-deb: building package 'libqcheck-ounit-ocaml' in '../libqcheck-ounit-ocaml_0.23-1_arm64.deb'.
-dpkg-deb: building package 'libqcheck-core-ocaml-dbgsym' in '../libqcheck-core-ocaml-dbgsym_0.23-1_arm64.deb'.
-dpkg-deb: building package 'libqcheck-ocaml-dbgsym' in '../libqcheck-ocaml-dbgsym_0.23-1_arm64.deb'.
+dpkg-deb: building package 'libqcheck-ounit-ocaml-dev' in '../libqcheck-ounit-ocaml-dev_0.23-1_arm64.deb'.
+dpkg-deb: building package 'libqcheck-ocaml-doc' in '../libqcheck-ocaml-doc_0.23-1_all.deb'.
  dpkg-genbuildinfo --build=binary -O../ocaml-qcheck_0.23-1_arm64.buildinfo
  dpkg-genchanges --build=binary -O../ocaml-qcheck_0.23-1_arm64.changes
 dpkg-genchanges: info: binary-only upload (no source code included)
@@ -703,12 +739,14 @@
 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/484890/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/484890/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/2160155 and its subdirectories
-I: Current time: Mon Jan 20 06:28:40 -12 2025
-I: pbuilder-time-stamp: 1737397720
+I: removing directory /srv/workspace/pbuilder/484890 and its subdirectories
+I: Current time: Mon Feb 23 14:52:56 +14 2026
+I: pbuilder-time-stamp: 1771807976