Diff of the two buildlogs:

--
--- b1/build.log	2023-04-10 14:15:41.918195044 +0000
+++ b2/build.log	2023-04-10 14:17:01.619537225 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sun May 12 08:37:57 -12 2024
-I: pbuilder-time-stamp: 1715546277
+I: Current time: Tue Apr 11 04:15:45 +14 2023
+I: pbuilder-time-stamp: 1681136145
 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 [./ocaml-fmt_0.9.0.orig.tar.bz2]
 I: copying [./ocaml-fmt_0.9.0-2.debian.tar.xz]
 I: Extracting source
-gpgv: Signature made Mon Nov 29 20:14:09 2021 -12
+gpgv: Signature made Tue Nov 30 22:14:09 2021 +14
 gpgv:                using RSA key 6DE24E97ECA886CC56E6250E21B8EEF1B1893081
 gpgv: Can't check signature: No public key
 dpkg-source: warning: cannot verify inline signature for ./ocaml-fmt_0.9.0-2.dsc: no acceptable signature found
@@ -27,11 +27,20 @@
 dpkg-source: info: applying 0001-Avoid-infinite-loop-in-test.patch
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/931/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/28428/tmp/hooks/D01_modify_environment starting
+debug: Running on codethink16-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
+lrwxrwxrwx 1 root root 4 Jan  6 03:20 /bin/sh -> dash
+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/28428/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/28428/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'
+  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'
@@ -41,38 +50,38 @@
   IFS=' 	
   '
   LANG='C'
-  LANGUAGE='en_US:en'
+  LANGUAGE='nl_BE:nl'
   LC_ALL='C'
   MAIL='/var/mail/root'
   OPTIND='1'
-  PATH='/usr/sbin:/usr/bin:/sbin:/bin:/usr/games'
+  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'
-  PPID='931'
+  PPID='28428'
   PS1='# '
   PS2='> '
   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.14sMRrS5/pbuilderrc_vSNV --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.14sMRrS5/b1 --logfile b1/build.log ocaml-fmt_0.9.0-2.dsc'
+  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.14sMRrS5/pbuilderrc_U6Jj --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.14sMRrS5/b2 --logfile b2/build.log --extrapackages usrmerge ocaml-fmt_0.9.0-2.dsc'
   SUDO_GID='117'
   SUDO_UID='110'
   SUDO_USER='jenkins'
   TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
+  TZ='/usr/share/zoneinfo/Etc/GMT-14'
   USER='root'
   USERNAME='root'
   _='/usr/bin/systemd-run'
   http_proxy='http://192.168.101.16:3128'
 I: uname -a
-  Linux codethink13-arm64 4.15.0-208-generic #220-Ubuntu SMP Mon Mar 20 14:28:12 UTC 2023 aarch64 GNU/Linux
+  Linux i-capture-the-hostname 4.15.0-208-generic #220-Ubuntu SMP Mon Mar 20 14:28:12 UTC 2023 aarch64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 May 10 04:48 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/931/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Apr  9 00:25 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/28428/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -167,7 +176,7 @@
 Get: 43 http://deb.debian.org/debian bookworm/main arm64 ocaml-nox all 4.13.1-4 [161 kB]
 Get: 44 http://deb.debian.org/debian bookworm/main arm64 ocamlbuild arm64 0.14.1-1 [1106 kB]
 Get: 45 http://deb.debian.org/debian bookworm/main arm64 opam-installer arm64 2.1.2-1 [1312 kB]
-Fetched 137 MB in 3s (49.9 MB/s)
+Fetched 137 MB in 5s (28.0 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 ... 19616 files and directories currently installed.)
@@ -361,8 +370,17 @@
 Writing extended state information...
 Building tag database...
  -> Finished parsing the build-deps
+Reading package lists...
+Building dependency tree...
+Reading state information...
+usrmerge is already the newest version (35).
+0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
 I: Building the package
-I: Running cd /build/ocaml-fmt-0.9.0/ && 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-fmt_0.9.0-2_source.changes
+I: user script /srv/workspace/pbuilder/28428/tmp/hooks/A99_set_merged_usr starting
+Re-configuring usrmerge...
+I: user script /srv/workspace/pbuilder/28428/tmp/hooks/A99_set_merged_usr finished
+hostname: Temporary failure in name resolution
+I: Running cd /build/ocaml-fmt-0.9.0/ && 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-fmt_0.9.0-2_source.changes
 dpkg-buildpackage: info: source package ocaml-fmt
 dpkg-buildpackage: info: source version 0.9.0-2
 dpkg-buildpackage: info: source distribution unstable
@@ -457,16 +475,16 @@
 make[1]: Entering directory '/build/ocaml-fmt-0.9.0'
 ocaml pkg/pkg.ml test
 Done.
-Formatted 794406 messages/second
-Formatted 907681 messages/second
-Formatted 929712 messages/second
-Formatted 904413 messages/second
-Formatted 927041 messages/second
-Formatted 933437 messages/second
-Formatted 945643 messages/second
-Formatted 923449 messages/second
-Formatted 927205 messages/second
-Formatted 935373 messages/second
+Formatted 620505 messages/second
+Formatted 542390 messages/second
+Formatted 690568 messages/second
+Formatted 619305 messages/second
+Formatted 506149 messages/second
+Formatted 683245 messages/second
+Formatted 687523 messages/second
+Formatted 663393 messages/second
+Formatted 682822 messages/second
+Formatted 665467 messages/second
 make[1]: Leaving directory '/build/ocaml-fmt-0.9.0'
    create-stamp debian/debhelper-build-stamp
    dh_prep
@@ -527,25 +545,25 @@
    dh_shlibdeps -a
    dh_installdeb
    dh_ocaml
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Asttypes
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Outcometree
 W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Longident
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Path
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Primitive
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Ident
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Misc
 W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Cmi_format
 W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Toploop
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Identifiable
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Env
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Load_path
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Outcometree
 W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Build_path_prefix_map
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Primitive
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Subst
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Path
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Load_path
 W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Types
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Type_immediacy
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Ident
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Location
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Warnings
-W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Misc
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Subst
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Asttypes
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Identifiable
 W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Parsetree
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Warnings
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Location
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Type_immediacy
+W: libfmt-ocaml-dev/libfmt-ocaml v0.9.0-2 doesn't resolve dependency on unit Env
    dh_gencontrol
 dpkg-gencontrol: warning: Depends field of package libfmt-ocaml-dev: substitution variable ${shlibs:Depends} used, but is not defined
 dpkg-gencontrol: warning: Depends field of package libfmt-ocaml: substitution variable ${shlibs:Depends} used, but is not defined
@@ -554,9 +572,9 @@
    dh_md5sums
    dh_builddeb
 dpkg-deb: building package 'libfmt-ocaml-dev' in '../libfmt-ocaml-dev_0.9.0-2_arm64.deb'.
-dpkg-deb: building package 'libfmt-ocaml-dev-dbgsym' in '../libfmt-ocaml-dev-dbgsym_0.9.0-2_arm64.deb'.
-dpkg-deb: building package 'libfmt-ocaml' in '../libfmt-ocaml_0.9.0-2_arm64.deb'.
 dpkg-deb: building package 'libfmt-ocaml-dbgsym' in '../libfmt-ocaml-dbgsym_0.9.0-2_arm64.deb'.
+dpkg-deb: building package 'libfmt-ocaml' in '../libfmt-ocaml_0.9.0-2_arm64.deb'.
+dpkg-deb: building package 'libfmt-ocaml-dev-dbgsym' in '../libfmt-ocaml-dev-dbgsym_0.9.0-2_arm64.deb'.
  dpkg-genbuildinfo --build=binary -O../ocaml-fmt_0.9.0-2_arm64.buildinfo
  dpkg-genchanges --build=binary -O../ocaml-fmt_0.9.0-2_arm64.changes
 dpkg-genchanges: info: binary-only upload (no source code included)
@@ -564,12 +582,14 @@
 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/28428/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/28428/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/931 and its subdirectories
-I: Current time: Sun May 12 08:38:41 -12 2024
-I: pbuilder-time-stamp: 1715546321
+I: removing directory /srv/workspace/pbuilder/28428 and its subdirectories
+I: Current time: Tue Apr 11 04:17:00 +14 2023
+I: pbuilder-time-stamp: 1681136220