Diff of the two buildlogs:

--
--- b1/build.log	2025-03-14 23:11:16.860620242 +0000
+++ b2/build.log	2025-03-14 23:13:02.459896795 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Fri Mar 14 11:10:10 -12 2025
-I: pbuilder-time-stamp: 1741993810
+I: Current time: Fri Apr 17 19:34:19 +14 2026
+I: pbuilder-time-stamp: 1776404059
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/unstable-reproducible-base.tgz]
 I: copying local configuration
@@ -24,51 +24,83 @@
 dpkg-source: info: applying remove-schemars.diff
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/1422508/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/3700011/tmp/hooks/D01_modify_environment starting
+debug: Running on infom02-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 17 05:34 /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/3700011/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/3700011/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'
+  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]="x86_64-pc-linux-gnu")
+  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=amd64
+  DEBIAN_FRONTEND=noninteractive
   DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=12 '
-  DISTRIBUTION='unstable'
-  HOME='/root'
-  HOST_ARCH='amd64'
+  DIRSTACK=()
+  DISTRIBUTION=unstable
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=x86_64
+  HOST_ARCH=amd64
   IFS=' 	
   '
-  INVOCATION_ID='9f08a2749d744354b7a69139fc0940da'
-  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='1422508'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=1fe7eb47ed7c475d930e8c5591b55500
+  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=3700011
   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.zubslTuY/pbuilderrc_Mnba --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.zubslTuY/b1 --logfile b1/build.log rust-ipnet_2.11.0-1.dsc'
-  SUDO_GID='109'
-  SUDO_UID='104'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  _='/usr/bin/systemd-run'
+  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.zubslTuY/pbuilderrc_Au8a --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.zubslTuY/b2 --logfile b2/build.log rust-ipnet_2.11.0-1.dsc'
+  SUDO_GID=109
+  SUDO_UID=104
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  _='I: set'
 I: uname -a
-  Linux infom01-amd64 6.1.0-31-cloud-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.128-1 (2025-02-07) x86_64 GNU/Linux
+  Linux i-capture-the-hostname 6.12.12+bpo-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.12-1~bpo12+1 (2025-02-23) x86_64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Mar  4 11:20 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/1422508/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Mar  4  2025 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/3700011/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -187,7 +219,7 @@
 Get: 75 http://deb.debian.org/debian unstable/main amd64 po-debconf all 1.0.21+nmu1 [248 kB]
 Get: 76 http://deb.debian.org/debian unstable/main amd64 debhelper all 13.24.1 [920 kB]
 Get: 77 http://deb.debian.org/debian unstable/main amd64 dh-cargo all 32 [10.6 kB]
-Fetched 137 MB in 1s (104 MB/s)
+Fetched 137 MB in 2s (75.4 MB/s)
 Preconfiguring packages ...
 Selecting previously unselected package libpython3.13-minimal:amd64.
 (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 ... 19785 files and directories currently installed.)
@@ -452,8 +484,8 @@
 Setting up tzdata (2025a-2) ...
 
 Current default time zone: 'Etc/UTC'
-Local time is now:      Fri Mar 14 23:11:07 UTC 2025.
-Universal Time is now:  Fri Mar 14 23:11:07 UTC 2025.
+Local time is now:      Fri Apr 17 05:35:43 UTC 2026.
+Universal Time is now:  Fri Apr 17 05:35:43 UTC 2026.
 Run 'dpkg-reconfigure tzdata' if you wish to change it.
 
 Setting up autotools-dev (20220109.1) ...
@@ -522,7 +554,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/rust-ipnet-2.11.0/ && 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  > ../rust-ipnet_2.11.0-1_source.changes
+I: user script /srv/workspace/pbuilder/3700011/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for unstable
+I: user script /srv/workspace/pbuilder/3700011/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/rust-ipnet-2.11.0/ && 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  > ../rust-ipnet_2.11.0-1_source.changes
 dpkg-buildpackage: info: source package rust-ipnet
 dpkg-buildpackage: info: source version 2.11.0-1
 dpkg-buildpackage: info: source distribution unstable
@@ -575,7 +611,7 @@
     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
 
 warning: `ipnet` (lib) generated 2 warnings
-    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.60s
+    Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.10s
 rustc 1.85.0+dfsg1-1 1
    create-stamp debian/debhelper-build-stamp
    dh_testroot -O--buildsystem=cargo
@@ -606,12 +642,14 @@
 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/3700011/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/3700011/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/1422508 and its subdirectories
-I: Current time: Fri Mar 14 11:11:16 -12 2025
-I: pbuilder-time-stamp: 1741993876
+I: removing directory /srv/workspace/pbuilder/3700011 and its subdirectories
+I: Current time: Fri Apr 17 19:36:01 +14 2026
+I: pbuilder-time-stamp: 1776404161