Diff of the two buildlogs:

--
--- b1/build.log	2025-01-11 14:04:24.118689511 +0000
+++ b2/build.log	2025-01-11 14:29:47.505381495 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sat Jan 11 01:45:54 -12 2025
-I: pbuilder-time-stamp: 1736603154
+I: Current time: Sun Jan 12 04:04:34 +14 2025
+I: pbuilder-time-stamp: 1736604274
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/unstable-reproducible-base.tgz]
 I: copying local configuration
@@ -34,52 +34,84 @@
 dpkg-source: info: applying fakeroot-for-setgroups.patch
 I: using fakeroot in build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/27529/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/5342/tmp/hooks/D01_modify_environment starting
+debug: Running on virt64a.
+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 Jan 11 14:04 /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/5342/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/5342/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='armhf'
-  DEBIAN_FRONTEND='noninteractive'
-  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=3 '
-  DISTRIBUTION='unstable'
-  HOME='/root'
-  HOST_ARCH='armhf'
+  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]="37" [3]="1" [4]="release" [5]="arm-unknown-linux-gnueabihf")
+  BASH_VERSION='5.2.37(1)-release'
+  BUILDDIR=/build/reproducible-path
+  BUILDUSERGECOS='second user,second room,second work-phone,second home-phone,second other'
+  BUILDUSERNAME=pbuilder2
+  BUILD_ARCH=armhf
+  DEBIAN_FRONTEND=noninteractive
+  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=4 '
+  DIRSTACK=()
+  DISTRIBUTION=unstable
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=arm
+  HOST_ARCH=armhf
   IFS=' 	
   '
-  INVOCATION_ID='127bb164f0cc4e52906a681f78e408de'
-  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='27529'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=79fcc19b2fb14fd5988212b9b08c0749
+  LANG=C
+  LANGUAGE=it_CH:it
+  LC_ALL=C
+  MACHTYPE=arm-unknown-linux-gnueabihf
+  MAIL=/var/mail/root
+  OPTERR=1
+  OPTIND=1
+  OSTYPE=linux-gnueabihf
+  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=5342
   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.gjta0xnl/pbuilderrc_6whd --distribution unstable --hookdir /etc/pbuilder/first-build-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/unstable-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.gjta0xnl/b1 --logfile b1/build.log ucspi-tcp_0.88-12.dsc'
-  SUDO_GID='110'
-  SUDO_UID='103'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  _='/usr/bin/systemd-run'
-  http_proxy='http://10.0.0.15:3142/'
+  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.gjta0xnl/pbuilderrc_JcRx --distribution unstable --hookdir /etc/pbuilder/rebuild-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/unstable-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.gjta0xnl/b2 --logfile b2/build.log ucspi-tcp_0.88-12.dsc'
+  SUDO_GID=114
+  SUDO_UID=108
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  _='I: set'
+  http_proxy=http://10.0.0.15:3142/
 I: uname -a
-  Linux virt32z 6.1.0-28-armmp-lpae #1 SMP Debian 6.1.119-1 (2024-11-22) armv7l GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-28-arm64 #1 SMP Debian 6.1.119-1 (2024-11-22) aarch64 GNU/Linux
 I: ls -l /bin
   lrwxrwxrwx 1 root root 7 Nov 22 14:40 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/27529/tmp/hooks/D02_print_environment finished
+I: user script /srv/workspace/pbuilder/5342/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -173,7 +205,7 @@
 Get: 46 http://deb.debian.org/debian unstable/main armhf python3-click all 8.1.8-1 [95.2 kB]
 Get: 47 http://deb.debian.org/debian unstable/main armhf python3-netifaces armhf 0.11.0-2+b5 [16.4 kB]
 Get: 48 http://deb.debian.org/debian unstable/main armhf python3-utf8-locale all 1.0.3-2 [13.1 kB]
-Fetched 25.7 MB in 2s (11.5 MB/s)
+Fetched 25.7 MB in 1s (30.3 MB/s)
 Preconfiguring packages ...
 Selecting previously unselected package libpython3.13-minimal:armhf.
 (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 ... 19562 files and directories currently installed.)
@@ -345,8 +377,8 @@
 Setting up tzdata (2024b-5) ...
 
 Current default time zone: 'Etc/UTC'
-Local time is now:      Sat Jan 11 13:46:28 UTC 2025.
-Universal Time is now:  Sat Jan 11 13:46:28 UTC 2025.
+Local time is now:      Sat Jan 11 14:05:44 UTC 2025.
+Universal Time is now:  Sat Jan 11 14:05:44 UTC 2025.
 Run 'dpkg-reconfigure tzdata' if you wish to change it.
 
 Setting up autotools-dev (20220109.1) ...
@@ -397,7 +429,11 @@
 fakeroot is already the newest version (1.36.2-1).
 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
 I: Building the package
-I: Running cd /build/reproducible-path/ucspi-tcp-0.88/ && 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  > ../ucspi-tcp_0.88-12_source.changes
+I: user script /srv/workspace/pbuilder/5342/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for unstable
+I: user script /srv/workspace/pbuilder/5342/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/ucspi-tcp-0.88/ && 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  > ../ucspi-tcp_0.88-12_source.changes
 dpkg-buildpackage: info: source package ucspi-tcp
 dpkg-buildpackage: info: source version 1:0.88-12
 dpkg-buildpackage: info: source distribution unstable
@@ -1517,9 +1553,9 @@
 - will spawn tcpclient at /build/reproducible-path/ucspi-tcp-0.88/tcpclient in a while
 - test_local_client_spew: setting up a listening socket at 127.0.0.1:6502
 - test_local_client_spew: starting /build/reproducible-path/ucspi-tcp-0.88/tcpclient -R 127.0.0.1 6502 sh -c 'set -e; exec <&6; exec cat'
-- started the client as pid 28649
+- started the client as pid 23268
 - waiting for a connection at 127.0.0.1:6502
-- accepted a connection at fd 5 from 127.0.0.1:45741
+- accepted a connection at fd 5 from 127.0.0.1:32811
 - closing the incoming connection
 - client exit code: 0; output: 'a01 hello\na02 bye\n'
 - /build/reproducible-path/ucspi-tcp-0.88/tcpclient seems fine
@@ -1561,9 +1597,9 @@
 - will spawn tcpclient at /build/reproducible-path/ucspi-tcp-0.88/ipv6/tcpclient in a while
 - test_local_client_spew: setting up a listening socket at 127.0.0.1:6502
 - test_local_client_spew: starting /build/reproducible-path/ucspi-tcp-0.88/ipv6/tcpclient -R 127.0.0.1 6502 sh -c 'set -e; exec <&6; exec cat'
-- started the client as pid 28716
+- started the client as pid 27020
 - waiting for a connection at 127.0.0.1:6502
-- accepted a connection at fd 5 from 127.0.0.1:44525
+- accepted a connection at fd 5 from 127.0.0.1:47045
 - closing the incoming connection
 - client exit code: 0; output: 'a01 hello\na02 bye\n'
 - /build/reproducible-path/ucspi-tcp-0.88/ipv6/tcpclient seems fine
@@ -1605,9 +1641,9 @@
 - will spawn tcpclient at /build/reproducible-path/ucspi-tcp-0.88/ipv6/tcpclient in a while
 - test_local_client_spew: setting up a listening socket at ::1:6502
 - test_local_client_spew: starting /build/reproducible-path/ucspi-tcp-0.88/ipv6/tcpclient -R ::1 6502 sh -c 'set -e; exec <&6; exec cat'
-- started the client as pid 28917
+- started the client as pid 4813
 - waiting for a connection at ::1:6502
-- accepted a connection at fd 5 from ::1:50455
+- accepted a connection at fd 5 from ::1:32777
 - closing the incoming connection
 - client exit code: 0; output: 'a01 hello\na02 bye\n'
 - /build/reproducible-path/ucspi-tcp-0.88/ipv6/tcpclient seems fine
@@ -1678,8 +1714,8 @@
    dh_md5sums
    dh_builddeb
 dpkg-deb: building package 'ucspi-tcp' in '../ucspi-tcp_0.88-12_armhf.deb'.
-dpkg-deb: building package 'ucspi-tcp-ipv6' in '../ucspi-tcp-ipv6_0.88-12_armhf.deb'.
 dpkg-deb: building package 'ucspi-tcp-dbgsym' in '../ucspi-tcp-dbgsym_0.88-12_armhf.deb'.
+dpkg-deb: building package 'ucspi-tcp-ipv6' in '../ucspi-tcp-ipv6_0.88-12_armhf.deb'.
 dpkg-deb: building package 'ucspi-tcp-ipv6-dbgsym' in '../ucspi-tcp-ipv6-dbgsym_0.88-12_armhf.deb'.
  dpkg-genbuildinfo --build=binary -O../ucspi-tcp_0.88-12_armhf.buildinfo
  dpkg-genchanges --build=binary -O../ucspi-tcp_0.88-12_armhf.changes
@@ -1688,12 +1724,14 @@
 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/5342/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/5342/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/27529 and its subdirectories
-I: Current time: Sat Jan 11 02:04:20 -12 2025
-I: pbuilder-time-stamp: 1736604260
+I: removing directory /srv/workspace/pbuilder/5342 and its subdirectories
+I: Current time: Sun Jan 12 04:29:42 +14 2025
+I: pbuilder-time-stamp: 1736605782