Diff of the two buildlogs:

--
--- b1/build.log	2023-04-11 12:20:55.961501553 +0000
+++ b2/build.log	2023-04-11 12:24:39.310097470 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Mon May 13 06:40:53 -12 2024
-I: pbuilder-time-stamp: 1715625653
+I: Current time: Wed Apr 12 02:20:58 +14 2023
+I: pbuilder-time-stamp: 1681215658
 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-silently_1.2.5.3.orig.tar.gz]
 I: copying [./haskell-silently_1.2.5.3-1.debian.tar.xz]
 I: Extracting source
-gpgv: Signature made Fri Oct 21 22:33:38 2022 -12
+gpgv: Signature made Sun Oct 23 00:33:38 2022 +14
 gpgv:                using RSA key 27D73CA5F5B5D7E01A5136F5D7A86780CC64403C
 gpgv:                issuer "iliastsi@debian.org"
 gpgv: Can't check signature: No public key
@@ -26,11 +26,20 @@
 dpkg-source: info: unpacking haskell-silently_1.2.5.3-1.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/2628/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/21370/tmp/hooks/D01_modify_environment starting
+debug: Running on codethink14-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/21370/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/21370/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'
@@ -40,38 +49,38 @@
   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='2628'
+  PPID='21370'
   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.40E2S2bY/pbuilderrc_XKdd --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.40E2S2bY/b1 --logfile b1/build.log haskell-silently_1.2.5.3-1.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.40E2S2bY/pbuilderrc_V8Bq --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.40E2S2bY/b2 --logfile b2/build.log --extrapackages usrmerge haskell-silently_1.2.5.3-1.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 codethink11-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 12 04:50 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/2628/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Apr 11 00:24 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/21370/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -217,7 +226,7 @@
 Get: 98 http://deb.debian.org/debian bookworm/main arm64 haskell-devscripts-minimal all 0.16.29 [65.6 kB]
 Get: 99 http://deb.debian.org/debian bookworm/main arm64 hscolour arm64 1.24.4-4+b1 [1308 kB]
 Get: 100 http://deb.debian.org/debian bookworm/main arm64 haskell-devscripts all 0.16.29 [17.8 kB]
-Fetched 299 MB in 8s (35.7 MB/s)
+Fetched 299 MB in 5s (54.6 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 ... 19616 files and directories currently installed.)
@@ -635,8 +644,17 @@
 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/haskell-silently-1.2.5.3/ && 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-silently_1.2.5.3-1_source.changes
+I: user script /srv/workspace/pbuilder/21370/tmp/hooks/A99_set_merged_usr starting
+Re-configuring usrmerge...
+I: user script /srv/workspace/pbuilder/21370/tmp/hooks/A99_set_merged_usr finished
+hostname: Temporary failure in name resolution
+I: Running cd /build/haskell-silently-1.2.5.3/ && 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-silently_1.2.5.3-1_source.changes
 dpkg-buildpackage: info: source package haskell-silently
 dpkg-buildpackage: info: source version 1.2.5.3-1
 dpkg-buildpackage: info: source distribution unstable
@@ -677,7 +695,7 @@
 Linking debian/hlibrary.setup ...
 perl -d:Confess -MDebian::Debhelper::Buildsystem::Haskell::Recipes=/.*/ \
 	-E 'configure_recipe'
-Running find . ! -newer /tmp/RdswktBygT -exec touch -d 1998-01-01 UTC {} ;
+Running find . ! -newer /tmp/uDswOYFP7P -exec touch -d 1998-01-01 UTC {} ;
 Running dh_listpackages
 libghc-silently-dev
 libghc-silently-prof
@@ -789,7 +807,7 @@
 creating dist-ghc/doc
 creating dist-ghc/doc/html
 creating dist-ghc/doc/html/silently
-/usr/bin/haddock '@dist-ghc/doc/html/silently/haddock-response18717-1.txt' '--mathjax=file:///usr/share/javascript/mathjax/MathJax.js'
+/usr/bin/haddock '@dist-ghc/doc/html/silently/haddock-response10338-1.txt' '--mathjax=file:///usr/share/javascript/mathjax/MathJax.js'
  100% (  7 /  7) in 'System.IO.Silently'
 Documentation created: dist-ghc/doc/html/silently/index.html,
 dist-ghc/doc/html/silently/silently.txt
@@ -1106,15 +1124,15 @@
 dh_installdeb -plibghc-silently-dev 
 dh_perl -plibghc-silently-dev 
 dh_shlibdeps -plibghc-silently-dev -- --ignore-missing-info
-dpkg-shlibdeps: warning: debian/libghc-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-ghc9.0.2.so contains an unresolvable reference to symbol newCAF: it's probably a plugin
+dpkg-shlibdeps: warning: debian/libghc-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-ghc9.0.2.so contains an unresolvable reference to symbol stg_sel_0_upd_info: it's probably a plugin
 dpkg-shlibdeps: warning: 18 other similar warnings have been skipped (use -v to see them all)
-dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-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-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-ghc9.0.2.so was not linked against libHSfilepath-1.4.2.1-ghc9.0.2.so (it uses none of the library's symbols)
-dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-ghc9.0.2.so was not linked against libHStime-1.9.3-ghc9.0.2.so (it uses none of the library's symbols)
 dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-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-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-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-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-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-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-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-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-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-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-ghc9.0.2.so was not linked against libHSfilepath-1.4.2.1-ghc9.0.2.so (it uses none of the library's symbols)
+dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-ghc9.0.2.so was not linked against libHStime-1.9.3-ghc9.0.2.so (it uses none of the library's symbols)
+dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/libghc-silently-dev/usr/lib/haskell-packages/ghc/lib/aarch64-linux-ghc-9.0.2/libHSsilently-1.2.5.3-H31j5J4Oc25zA6fMk6qKZ-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)
 dh_installdeb -plibghc-silently-prof 
 dh_perl -plibghc-silently-prof 
 dh_shlibdeps -plibghc-silently-prof -- --ignore-missing-info
@@ -1147,12 +1165,14 @@
 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/21370/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/21370/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/2628 and its subdirectories
-I: Current time: Mon May 13 06:43:55 -12 2024
-I: pbuilder-time-stamp: 1715625835
+I: removing directory /srv/workspace/pbuilder/21370 and its subdirectories
+I: Current time: Wed Apr 12 02:24:38 +14 2023
+I: pbuilder-time-stamp: 1681215878