Diff of the two buildlogs:

--
--- b1/build.log	2023-06-02 01:25:22.796705833 +0000
+++ b2/build.log	2023-06-02 01:29:45.661196921 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Wed Jul  3 19:44:27 -12 2024
-I: pbuilder-time-stamp: 1720079067
+I: Current time: Fri Jun  2 15:25:25 +14 2023
+I: pbuilder-time-stamp: 1685669125
 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 [./haskell-concurrent-supply_0.1.8.orig.tar.gz]
 I: copying [./haskell-concurrent-supply_0.1.8-7.debian.tar.xz]
 I: Extracting source
-gpgv: Signature made Tue Jan  3 04:16:46 2023 -12
+gpgv: Signature made Wed Jan  4 06:16:46 2023 +14
 gpgv:                using RSA key 6E7434F5897D43B17FCD57B753D5BC64B52378A2
 gpgv:                issuer "swt@techie.net"
 gpgv: Can't check signature: No public key
@@ -29,52 +29,84 @@
 dpkg-source: info: applying no-rts-n
 I: using fakeroot in build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/15394/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/20028/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
+'/bin/sh' -> '/bin/bash'
+lrwxrwxrwx 1 root root 9 Jun  2 15:25 /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/20028/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/20028/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='15394'
-  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=20028
   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.7sa668Pm/pbuilderrc_zdQw --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.7sa668Pm/b1 --logfile b1/build.log haskell-concurrent-supply_0.1.8-7.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.7sa668Pm/pbuilderrc_8HfI --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.7sa668Pm/b2 --logfile b2/build.log --extrapackages usrmerge haskell-concurrent-supply_0.1.8-7.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 codethink15-arm64 4.15.0-212-generic #223-Ubuntu SMP Tue May 23 13:09:17 UTC 2023 aarch64 GNU/Linux
+  Linux i-capture-the-hostname 4.15.0-212-generic #223-Ubuntu SMP Tue May 23 13:09:17 UTC 2023 aarch64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Jul  3 02:01 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/15394/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 May 27 00:24 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/20028/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -231,7 +263,7 @@
 Get: 100 http://deb.debian.org/debian bookworm/main arm64 libghc-hashable-dev arm64 1.3.5.0-2+b2 [153 kB]
 Get: 101 http://deb.debian.org/debian bookworm/main arm64 libghc-hashable-doc all 1.3.5.0-2 [87.6 kB]
 Get: 102 http://deb.debian.org/debian bookworm/main arm64 libghc-hashable-prof arm64 1.3.5.0-2+b2 [147 kB]
-Fetched 298 MB in 5s (58.8 MB/s)
+Fetched 298 MB in 4s (67.1 MB/s)
 debconf: delaying package configuration, since apt-utils is not installed
 Selecting previously unselected package libbsd0: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 ... 19611 files and directories currently installed.)
@@ -660,10 +692,15 @@
 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/haskell-concurrent-supply-0.1.8/ && 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  > ../haskell-concurrent-supply_0.1.8-7_source.changes
+I: user script /srv/workspace/pbuilder/20028/tmp/hooks/A99_set_merged_usr starting
+Re-configuring usrmerge...
+I: user script /srv/workspace/pbuilder/20028/tmp/hooks/A99_set_merged_usr finished
+hostname: Temporary failure in name resolution
+I: Running cd /build/haskell-concurrent-supply-0.1.8/ && 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  > ../haskell-concurrent-supply_0.1.8-7_source.changes
 dpkg-buildpackage: info: source package haskell-concurrent-supply
 dpkg-buildpackage: info: source version 0.1.8-7
 dpkg-buildpackage: info: source distribution unstable
@@ -709,7 +746,7 @@
 Linking debian/hlibrary.setup ...
 perl -d:Confess -MDebian::Debhelper::Buildsystem::Haskell::Recipes=/.*/ \
 	-E 'configure_recipe'
-Running find . ! -newer /tmp/SgK6f1S93k -exec touch -d 1998-01-01 UTC {} ;
+Running find . ! -newer /tmp/GYOjbmWRGt -exec touch -d 1998-01-01 UTC {} ;
 Running dh_listpackages
 libghc-concurrent-supply-dev
 libghc-concurrent-supply-prof
@@ -851,7 +888,7 @@
 creating dist-ghc/doc
 creating dist-ghc/doc/html
 creating dist-ghc/doc/html/concurrent-supply
-/usr/bin/haddock '@dist-ghc/doc/html/concurrent-supply/haddock-response26985-1.txt' '--mathjax=file:///usr/share/javascript/mathjax/MathJax.js'
+/usr/bin/haddock '@dist-ghc/doc/html/concurrent-supply/haddock-response25159-1.txt' '--mathjax=file:///usr/share/javascript/mathjax/MathJax.js'
  100% (  9 /  9) in 'Control.Concurrent.Supply'
 Documentation created: dist-ghc/doc/html/concurrent-supply/index.html,
 dist-ghc/doc/html/concurrent-supply/concurrent-supply.txt
@@ -1200,20 +1237,20 @@
 dh_installdeb -plibghc-concurrent-supply-dev 
 dh_perl -plibghc-concurrent-supply-dev 
 dh_shlibdeps -plibghc-concurrent-supply-dev -- --ignore-missing-info
-dpkg-shlibdeps: warning: debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so contains an unresolvable reference to symbol newCAF: it's probably a plugin
+dpkg-shlibdeps: warning: debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so contains an unresolvable reference to symbol stg_upd_frame_info: it's probably a plugin
 dpkg-shlibdeps: warning: 13 other similar warnings have been skipped (use -v to see them all)
-dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHSbinary-0.8.8.0-ghc9.0.2.so (it uses none of the library's symbols)
-dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHStemplate-haskell-2.17.0.0-ghc9.0.2.so (it uses none of the library's symbols)
-dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHSdeepseq-1.4.5.0-ghc9.0.2.so (it uses none of the library's symbols)
-dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libgmp.so.10 (it uses none of the library's symbols)
 dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHSarray-0.5.4.0-ghc9.0.2.so (it uses none of the library's symbols)
+dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHStext-1.2.5.0-ghc9.0.2.so (it uses none of the library's symbols)
+dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHSpretty-1.1.3.6-ghc9.0.2.so (it uses none of the library's symbols)
+dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libgmp.so.10 (it uses none of the library's symbols)
 dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHSbytestring-0.10.12.1-ghc9.0.2.so (it uses none of the library's symbols)
+dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHSbinary-0.8.8.0-ghc9.0.2.so (it uses none of the library's symbols)
+dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHSghc-boot-th-9.0.2-ghc9.0.2.so (it uses none of the library's symbols)
+dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHStemplate-haskell-2.17.0.0-ghc9.0.2.so (it uses none of the library's symbols)
+dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHSghc-bignum-1.1-ghc9.0.2.so (it uses none of the library's symbols)
 dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHScontainers-0.6.4.1-ghc9.0.2.so (it uses none of the library's symbols)
 dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libm.so.6 (it uses none of the library's symbols)
-dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHSpretty-1.1.3.6-ghc9.0.2.so (it uses none of the library's symbols)
-dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHSghc-bignum-1.1-ghc9.0.2.so (it uses none of the library's symbols)
-dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHSghc-boot-th-9.0.2-ghc9.0.2.so (it uses none of the library's symbols)
-dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHStext-1.2.5.0-ghc9.0.2.so (it uses none of the library's symbols)
+dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-concurrent-supply-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSconcurrent-supply-0.1.8-E9YnzpQBK1cAdwZ9eAM2JY-ghc9.0.2.so was not linked against libHSdeepseq-1.4.5.0-ghc9.0.2.so (it uses none of the library's symbols)
 dh_installdeb -plibghc-concurrent-supply-prof 
 dh_perl -plibghc-concurrent-supply-prof 
 dh_shlibdeps -plibghc-concurrent-supply-prof -- --ignore-missing-info
@@ -1251,12 +1288,14 @@
 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/20028/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/20028/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/15394 and its subdirectories
-I: Current time: Wed Jul  3 19:48:21 -12 2024
-I: pbuilder-time-stamp: 1720079301
+I: removing directory /srv/workspace/pbuilder/20028 and its subdirectories
+I: Current time: Fri Jun  2 15:29:44 +14 2023
+I: pbuilder-time-stamp: 1685669384