Diff of the two buildlogs:

--
--- b1/build.log	2024-04-07 17:24:13.356334066 +0000
+++ b2/build.log	2024-04-07 17:25:04.630150777 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sat May 10 11:46:46 -12 2025
-I: pbuilder-time-stamp: 1746920806
+I: Current time: Mon Apr  8 07:24:17 +14 2024
+I: pbuilder-time-stamp: 1712510657
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/trixie-reproducible-base.tgz]
 I: copying local configuration
@@ -26,54 +26,86 @@
 dpkg-source: info: unpacking libsocket-msghdr-perl_0.05-2.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/51815/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/40401/tmp/hooks/D01_modify_environment starting
+debug: Running on ionos2-i386.
+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  7 17:24 /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/40401/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/40401/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='i386'
-  DEBIAN_FRONTEND='noninteractive'
-  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=22 '
-  DISTRIBUTION='trixie'
-  HOME='/root'
-  HOST_ARCH='i386'
+  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]="i686-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=i386
+  DEBIAN_FRONTEND=noninteractive
+  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=7 '
+  DIRSTACK=()
+  DISTRIBUTION=trixie
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=i686
+  HOST_ARCH=i386
   IFS=' 	
   '
-  INVOCATION_ID='fd7cabb5f0a64f9588b55b90b1d690b1'
-  LANG='C'
-  LANGUAGE='en_US:en'
-  LC_ALL='C'
-  LD_LIBRARY_PATH='/usr/lib/libeatmydata'
-  LD_PRELOAD='libeatmydata.so'
-  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='51815'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=525fdbc246854c4f9e491a526a64967d
+  LANG=C
+  LANGUAGE=de_CH:de
+  LC_ALL=C
+  LD_LIBRARY_PATH=/usr/lib/libeatmydata
+  LD_PRELOAD=libeatmydata.so
+  MACHTYPE=i686-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=40401
   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.h5BCJoB1/pbuilderrc_2fa2 --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.h5BCJoB1/b1 --logfile b1/build.log libsocket-msghdr-perl_0.05-2.dsc'
-  SUDO_GID='112'
-  SUDO_UID='107'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  _='/usr/bin/systemd-run'
-  http_proxy='http://85.184.249.68:3128'
+  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.h5BCJoB1/pbuilderrc_sfE8 --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.h5BCJoB1/b2 --logfile b2/build.log libsocket-msghdr-perl_0.05-2.dsc'
+  SUDO_GID=112
+  SUDO_UID=107
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  _='I: set'
+  http_proxy=http://78.137.99.97:3128
 I: uname -a
-  Linux ionos6-i386 6.1.0-18-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.76-1 (2024-02-01) x86_64 GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-18-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.76-1 (2024-02-01) x86_64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 May  8 17:46 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/51815/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Apr  7 11:25 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/40401/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: 29 http://deb.debian.org/debian trixie/main i386 po-debconf all 1.0.21+nmu1 [248 kB]
 Get: 30 http://deb.debian.org/debian trixie/main i386 debhelper all 13.15.3 [901 kB]
 Get: 31 http://deb.debian.org/debian trixie/main i386 libperl-dev i386 5.38.2-3 [1194 kB]
-Fetched 20.5 MB in 0s (89.7 MB/s)
+Fetched 20.5 MB in 0s (59.3 MB/s)
 debconf: delaying package configuration, since apt-utils is not installed
 Selecting previously unselected package sensible-utils.
 (Reading database ... 
(Reading database ... 5%
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(Reading database ... 90%
(Reading database ... 95%
(Reading database ... 100%
(Reading database ... 19876 files and directories currently installed.)
@@ -282,7 +314,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/libsocket-msghdr-perl-0.05/ && 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  > ../libsocket-msghdr-perl_0.05-2_source.changes
+I: user script /srv/workspace/pbuilder/40401/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/40401/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/libsocket-msghdr-perl-0.05/ && 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  > ../libsocket-msghdr-perl_0.05-2_source.changes
 dpkg-buildpackage: info: source package libsocket-msghdr-perl
 dpkg-buildpackage: info: source version 0.05-2
 dpkg-buildpackage: info: source distribution unstable
@@ -304,7 +340,7 @@
 Writing Makefile for Socket::MsgHdr
 Writing MYMETA.yml and MYMETA.json
    dh_auto_build
-	make -j22
+	make -j7
 make[1]: Entering directory '/build/reproducible-path/libsocket-msghdr-perl-0.05'
 Running Mkbootstrap for MsgHdr ()
 "/usr/bin/perl" "/usr/share/perl/5.38/ExtUtils/xsubpp"  -typemap '/usr/share/perl/5.38/ExtUtils/typemap'  MsgHdr.xs > MsgHdr.xsc
@@ -321,7 +357,7 @@
 Manifying 1 pod document
 make[1]: Leaving directory '/build/reproducible-path/libsocket-msghdr-perl-0.05'
    dh_auto_test
-	make -j22 test TEST_VERBOSE=1
+	make -j7 test TEST_VERBOSE=1
 make[1]: Entering directory '/build/reproducible-path/libsocket-msghdr-perl-0.05'
 "/usr/bin/perl" -MExtUtils::Command::MM -e 'cp_nonempty' -- MsgHdr.bs blib/arch/auto/Socket/MsgHdr/MsgHdr.bs 644
 PERL_DL_NONLAZY=1 "/usr/bin/perl" "-MExtUtils::Command::MM" "-MTest::Harness" "-e" "undef *Test::Harness::Switches; test_harness(1, 'blib/lib', 'blib/arch')" t/*.t
@@ -383,13 +419,13 @@
 t/pod-coverage.t .. skipped: Test::Pod::Coverage required
 t/pod.t ........... skipped: Test::Pod 1.00 required for testing POD
 All tests successful.
-Files=6, Tests=43,  1 wallclock secs ( 0.02 usr  0.00 sys +  0.34 cusr  0.04 csys =  0.40 CPU)
+Files=6, Tests=43,  1 wallclock secs ( 0.04 usr  0.00 sys +  0.54 cusr  0.06 csys =  0.64 CPU)
 Result: PASS
 make[1]: Leaving directory '/build/reproducible-path/libsocket-msghdr-perl-0.05'
    create-stamp debian/debhelper-build-stamp
    dh_prep
    dh_auto_install --destdir=debian/libsocket-msghdr-perl/
-	make -j22 install DESTDIR=/build/reproducible-path/libsocket-msghdr-perl-0.05/debian/libsocket-msghdr-perl AM_UPDATE_INFO_DIR=no PREFIX=/usr
+	make -j7 install DESTDIR=/build/reproducible-path/libsocket-msghdr-perl-0.05/debian/libsocket-msghdr-perl AM_UPDATE_INFO_DIR=no PREFIX=/usr
 make[1]: Entering directory '/build/reproducible-path/libsocket-msghdr-perl-0.05'
 "/usr/bin/perl" -MExtUtils::Command::MM -e 'cp_nonempty' -- MsgHdr.bs blib/arch/auto/Socket/MsgHdr/MsgHdr.bs 644
 Manifying 1 pod document
@@ -424,12 +460,14 @@
 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/40401/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/40401/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/51815 and its subdirectories
-I: Current time: Sat May 10 11:47:11 -12 2025
-I: pbuilder-time-stamp: 1746920831
+I: removing directory /srv/workspace/pbuilder/40401 and its subdirectories
+I: Current time: Mon Apr  8 07:25:03 +14 2024
+I: pbuilder-time-stamp: 1712510703