Diff of the two buildlogs:

--
--- b1/build.log	2025-03-24 01:31:00.311655292 +0000
+++ b2/build.log	2025-03-24 01:32:21.568003000 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sat Apr 25 19:52:33 -12 2026
-I: pbuilder-time-stamp: 1777189953
+I: Current time: Mon Mar 24 15:31:03 +14 2025
+I: pbuilder-time-stamp: 1742779863
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/trixie-reproducible-base.tgz]
 I: copying local configuration
@@ -22,52 +22,84 @@
 dpkg-source: info: unpacking coq-quickchick_2.1.0-1.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/3594357/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/2713904/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 Mar 24 01:31 /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/2713904/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/2713904/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='231d66cb5b314051919b693f734a2bf7'
-  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='3594357'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=0de43918cb654eb1ac11b7e2578443cf
+  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=2713904
   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.zfSCLDdi/pbuilderrc_AqkO --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.zfSCLDdi/b1 --logfile b1/build.log coq-quickchick_2.1.0-1.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.zfSCLDdi/pbuilderrc_T34D --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.zfSCLDdi/b2 --logfile b2/build.log coq-quickchick_2.1.0-1.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 codethink03-arm64 6.1.0-32-cloud-arm64 #1 SMP Debian 6.1.129-1 (2025-03-06) aarch64 GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-32-cloud-arm64 #1 SMP Debian 6.1.129-1 (2025-03-06) aarch64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Mar  4  2025 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/3594357/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Mar  4 11:20 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/2713904/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -219,7 +251,7 @@
 Get: 88 http://deb.debian.org/debian trixie/main arm64 menhir arm64 20240715+ds-1+b1 [1572 kB]
 Get: 89 http://deb.debian.org/debian trixie/main arm64 ocaml-dune arm64 3.17.2-1 [5587 kB]
 Get: 90 http://deb.debian.org/debian trixie/main arm64 ocamlbuild arm64 0.16.1-1 [1283 kB]
-Fetched 390 MB in 4s (105 MB/s)
+Fetched 390 MB in 1s (308 MB/s)
 Preconfiguring packages ...
 Selecting previously unselected package liblocale-gettext-perl.
 (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 ... 19899 files and directories currently installed.)
@@ -521,8 +553,8 @@
 Setting up tzdata (2025a-2) ...
 
 Current default time zone: 'Etc/UTC'
-Local time is now:      Sun Apr 26 07:53:15 UTC 2026.
-Universal Time is now:  Sun Apr 26 07:53:15 UTC 2026.
+Local time is now:      Mon Mar 24 01:31:34 UTC 2025.
+Universal Time is now:  Mon Mar 24 01:31:34 UTC 2025.
 Run 'dpkg-reconfigure tzdata' if you wish to change it.
 
 Setting up autotools-dev (20220109.1) ...
@@ -606,7 +638,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/coq-quickchick-2.1.0/ && 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  > ../coq-quickchick_2.1.0-1_source.changes
+I: user script /srv/workspace/pbuilder/2713904/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/2713904/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/coq-quickchick-2.1.0/ && 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  > ../coq-quickchick_2.1.0-1_source.changes
 dpkg-buildpackage: info: source package coq-quickchick
 dpkg-buildpackage: info: source version 2.1.0-1
 dpkg-buildpackage: info: source distribution unstable
@@ -653,7 +689,7 @@
 dune build -p coq-quickchick
 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 && /usr/bin/ocamlc.opt -w -40 -rectypes -warn-error -3 -w -8-27+40 -g -bin-annot -bin-annot-occurrences -I plugin/.quickchick_plugin.objs/byte -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/boot -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/clib -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/config -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/engine -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/gramlib -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/interp -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/kernel -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/lib -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/library -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/parsing -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/perf -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/plugins/extraction -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/plugins/ltac -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/pretyping -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/printing -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/proofs -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/tactics -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/vernac -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/coq-core/vm -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/dynlink -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/findlib -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/str -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/threads -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/unix -I /usr/lib/aarch64-linux-gnu/ocaml/5.3.0/zarith -intf-suffix .ml -no-alias-deps -open Quickchick_plugin -o plugin/.quickchick_plugin.objs/byte/quickchick_plugin__GenericLib.cmo -c -impl plugin/genericLib.ml)
 File "plugin/genericLib.ml", line 839, characters 24-38:
@@ -880,7 +916,7 @@
 dune install coq-quickchick --destdir=/build/reproducible-path/coq-quickchick-2.1.0/debian/tmp --prefix=/usr --libdir=/usr/lib/aarch64-linux-gnu/ocaml/5.3.0
 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
 find /build/reproducible-path/coq-quickchick-2.1.0/debian/tmp -name LICENSE -delete
 help2man /build/reproducible-path/coq-quickchick-2.1.0/debian/tmp/usr/bin/quickChick --no-discard-stderr > debian/quickChick.1
@@ -913,9 +949,9 @@
 dpkg-gencontrol: warning: package libcoq-quickchick: substitution variable ${ocaml:Depends} unused, but is defined
    dh_md5sums
    dh_builddeb
-dpkg-deb: building package 'libcoq-quickchick' in '../libcoq-quickchick_2.1.0-1_arm64.deb'.
-dpkg-deb: building package 'libcoq-quickchick-dbgsym' in '../libcoq-quickchick-dbgsym_2.1.0-1_arm64.deb'.
 dpkg-deb: building package 'quickchick' in '../quickchick_2.1.0-1_arm64.deb'.
+dpkg-deb: building package 'libcoq-quickchick-dbgsym' in '../libcoq-quickchick-dbgsym_2.1.0-1_arm64.deb'.
+dpkg-deb: building package 'libcoq-quickchick' in '../libcoq-quickchick_2.1.0-1_arm64.deb'.
 dpkg-deb: building package 'quickchick-dbgsym' in '../quickchick-dbgsym_2.1.0-1_arm64.deb'.
  dpkg-genbuildinfo --build=binary -O../coq-quickchick_2.1.0-1_arm64.buildinfo
  dpkg-genchanges --build=binary -O../coq-quickchick_2.1.0-1_arm64.changes
@@ -924,12 +960,14 @@
 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/2713904/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/2713904/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/3594357 and its subdirectories
-I: Current time: Sat Apr 25 19:53:58 -12 2026
-I: pbuilder-time-stamp: 1777190038
+I: removing directory /srv/workspace/pbuilder/2713904 and its subdirectories
+I: Current time: Mon Mar 24 15:32:20 +14 2025
+I: pbuilder-time-stamp: 1742779940