Diff of the two buildlogs:

--
--- b1/build.log	2024-04-22 23:28:16.751101669 +0000
+++ b2/build.log	2024-04-22 23:30:33.689242084 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sun May 25 17:50:37 -12 2025
-I: pbuilder-time-stamp: 1748238637
+I: Current time: Tue Apr 23 13:28:19 +14 2024
+I: pbuilder-time-stamp: 1713828499
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/trixie-reproducible-base.tgz]
 I: copying local configuration
@@ -25,52 +25,84 @@
 dpkg-source: info: unpacking liblinux-fd-perl_0.016-1.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/197840/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/655046/tmp/hooks/D01_modify_environment starting
+debug: Running on ionos11-amd64.
+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 Apr 22 23:28 /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/655046/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/655046/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='amd64'
-  DEBIAN_FRONTEND='noninteractive'
-  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=42 '
-  DISTRIBUTION='trixie'
-  HOME='/root'
-  HOST_ARCH='amd64'
+  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]="21" [3]="1" [4]="release" [5]="x86_64-pc-linux-gnu")
+  BASH_VERSION='5.2.21(1)-release'
+  BUILDDIR=/build/reproducible-path
+  BUILDUSERGECOS='second user,second room,second work-phone,second home-phone,second other'
+  BUILDUSERNAME=pbuilder2
+  BUILD_ARCH=amd64
+  DEBIAN_FRONTEND=noninteractive
+  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=20 '
+  DIRSTACK=()
+  DISTRIBUTION=trixie
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=x86_64
+  HOST_ARCH=amd64
   IFS=' 	
   '
-  INVOCATION_ID='94938dffbac94b5e9ee4cea63df9f568'
-  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='197840'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=8dccaf12968741cd86eb2edc31c94c99
+  LANG=C
+  LANGUAGE=et_EE:et
+  LC_ALL=C
+  MACHTYPE=x86_64-pc-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=655046
   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.CLk99vB2/pbuilderrc_bpt6 --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.CLk99vB2/b1 --logfile b1/build.log liblinux-fd-perl_0.016-1.dsc'
-  SUDO_GID='110'
-  SUDO_UID='105'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  _='/usr/bin/systemd-run'
-  http_proxy='http://213.165.73.152:3128'
+  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.CLk99vB2/pbuilderrc_w6IC --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.CLk99vB2/b2 --logfile b2/build.log liblinux-fd-perl_0.016-1.dsc'
+  SUDO_GID=111
+  SUDO_UID=106
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  _='I: set'
+  http_proxy=http://46.16.76.132:3128
 I: uname -a
-  Linux ionos5-amd64 6.6.13+bpo-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.6.13-1~bpo12+1 (2024-02-15) x86_64 GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-20-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.85-1 (2024-04-11) x86_64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 May 25 19:07 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/197840/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Apr 22 12:43 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/655046/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -143,7 +175,7 @@
 Get: 30 http://deb.debian.org/debian trixie/main amd64 debhelper all 13.15.3 [901 kB]
 Get: 31 http://deb.debian.org/debian trixie/main amd64 libmodule-build-perl all 0.423400-2 [252 kB]
 Get: 32 http://deb.debian.org/debian trixie/main amd64 libperl-dev amd64 5.38.2-3 [1087 kB]
-Fetched 20.4 MB in 3s (6033 kB/s)
+Fetched 20.4 MB in 1s (23.6 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 ... 19890 files and directories currently installed.)
@@ -288,7 +320,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/liblinux-fd-perl-0.016/ && 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  > ../liblinux-fd-perl_0.016-1_source.changes
+I: user script /srv/workspace/pbuilder/655046/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/655046/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/liblinux-fd-perl-0.016/ && 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  > ../liblinux-fd-perl_0.016-1_source.changes
 dpkg-buildpackage: info: source package liblinux-fd-perl
 dpkg-buildpackage: info: source version 0.016-1
 dpkg-buildpackage: info: source distribution unstable
@@ -356,7 +392,7 @@
 1..10
 ok
 All tests successful.
-Files=3, Tests=32,  1 wallclock secs ( 0.01 usr  0.02 sys +  0.17 cusr  0.04 csys =  0.24 CPU)
+Files=3, Tests=32,  2 wallclock secs ( 0.04 usr  0.01 sys +  0.36 cusr  0.07 csys =  0.48 CPU)
 Result: PASS
    create-stamp debian/debhelper-build-stamp
    dh_prep
@@ -364,16 +400,16 @@
 	/usr/bin/perl Build install --destdir /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl --create_packlist 0
 Building Linux-FD
 Files found in blib/arch: installing files in blib/lib into architecture dependent library tree
-Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/lib/x86_64-linux-gnu/perl5/5.38/auto/Linux/FD/FD.bs
 Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/lib/x86_64-linux-gnu/perl5/5.38/auto/Linux/FD/FD.so
+Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/lib/x86_64-linux-gnu/perl5/5.38/auto/Linux/FD/FD.bs
 Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/lib/x86_64-linux-gnu/perl5/5.38/Linux/FD.pm
-Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/lib/x86_64-linux-gnu/perl5/5.38/Linux/FD/Signal.pm
-Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/lib/x86_64-linux-gnu/perl5/5.38/Linux/FD/Timer.pm
 Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/lib/x86_64-linux-gnu/perl5/5.38/Linux/FD/Event.pm
-Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/share/man/man3/Linux::FD::Timer.3pm
+Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/lib/x86_64-linux-gnu/perl5/5.38/Linux/FD/Timer.pm
+Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/lib/x86_64-linux-gnu/perl5/5.38/Linux/FD/Signal.pm
 Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/share/man/man3/Linux::FD.3pm
-Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/share/man/man3/Linux::FD::Signal.3pm
 Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/share/man/man3/Linux::FD::Event.3pm
+Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/share/man/man3/Linux::FD::Timer.3pm
+Installing /build/reproducible-path/liblinux-fd-perl-0.016/debian/liblinux-fd-perl/usr/share/man/man3/Linux::FD::Signal.3pm
    dh_installdocs
    dh_installchangelogs
    debian/rules override_dh_installexamples
@@ -397,8 +433,8 @@
    dh_gencontrol
    dh_md5sums
    dh_builddeb
-dpkg-deb: building package 'liblinux-fd-perl-dbgsym' in '../liblinux-fd-perl-dbgsym_0.016-1_amd64.deb'.
 dpkg-deb: building package 'liblinux-fd-perl' in '../liblinux-fd-perl_0.016-1_amd64.deb'.
+dpkg-deb: building package 'liblinux-fd-perl-dbgsym' in '../liblinux-fd-perl-dbgsym_0.016-1_amd64.deb'.
  dpkg-genbuildinfo --build=binary -O../liblinux-fd-perl_0.016-1_amd64.buildinfo
  dpkg-genchanges --build=binary -O../liblinux-fd-perl_0.016-1_amd64.changes
 dpkg-genchanges: info: binary-only upload (no source code included)
@@ -406,12 +442,14 @@
 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/655046/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/655046/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/197840 and its subdirectories
-I: Current time: Sun May 25 17:51:15 -12 2025
-I: pbuilder-time-stamp: 1748238675
+I: removing directory /srv/workspace/pbuilder/655046 and its subdirectories
+I: Current time: Tue Apr 23 13:30:32 +14 2024
+I: pbuilder-time-stamp: 1713828632