Diff of the two buildlogs:

--
--- b1/build.log	2024-04-28 06:15:53.398887432 +0000
+++ b2/build.log	2024-04-28 06:18:30.944155289 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sat May 31 00:36:30 -12 2025
-I: pbuilder-time-stamp: 1748694990
+I: Current time: Sun Apr 28 20:15:56 +14 2024
+I: pbuilder-time-stamp: 1714284956
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/trixie-reproducible-base.tgz]
 I: copying local configuration
@@ -25,51 +25,83 @@
 dpkg-source: info: unpacking python-rx_4.0.4-3.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/269398/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/1173859/tmp/hooks/D01_modify_environment starting
+debug: Running on infom01-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 28 06:16 /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/1173859/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/1173859/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]="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=12 '
-  DISTRIBUTION='trixie'
-  HOME='/root'
-  HOST_ARCH='amd64'
+  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='932eeda70e394b0faef0798870c44f3b'
-  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='269398'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=7756e4a5c488408297ac0287e0bdc353
+  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=1173859
   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.YbJuNsDP/pbuilderrc_CdJL --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.YbJuNsDP/b1 --logfile b1/build.log python-rx_4.0.4-3.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.YbJuNsDP/pbuilderrc_a5iC --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.YbJuNsDP/b2 --logfile b2/build.log python-rx_4.0.4-3.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 infom02-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-cloud-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 24 13:34 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/269398/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Apr 23 11:24 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/1173859/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -293,7 +325,7 @@
 Get: 108 http://deb.debian.org/debian trixie/main amd64 python3-virtualenv all 20.25.1+ds-1 [70.1 kB]
 Get: 109 http://deb.debian.org/debian trixie/main amd64 python3-poetry all 1.8.2+dfsg-1 [179 kB]
 Get: 110 http://deb.debian.org/debian trixie/main amd64 python3-pytest all 7.4.4-3 [239 kB]
-Fetched 41.7 MB in 1s (48.5 MB/s)
+Fetched 41.7 MB in 0s (99.1 MB/s)
 debconf: delaying package configuration, since apt-utils is not installed
 dpkg: libssl3:amd64: dependency problems, but removing anyway as you requested:
  libkrb5-3:amd64 depends on libssl3 (>= 3.0.0).
@@ -661,8 +693,8 @@
 Setting up tzdata (2024a-3) ...
 
 Current default time zone: 'Etc/UTC'
-Local time is now:      Sat May 31 12:37:23 UTC 2025.
-Universal Time is now:  Sat May 31 12:37:23 UTC 2025.
+Local time is now:      Sun Apr 28 06:16:43 UTC 2024.
+Universal Time is now:  Sun Apr 28 06:16:43 UTC 2024.
 Run 'dpkg-reconfigure tzdata' if you wish to change it.
 
 Setting up autotools-dev (20220109.1) ...
@@ -775,7 +807,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/python-rx-4.0.4/ && 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  > ../python-rx_4.0.4-3_source.changes
+I: user script /srv/workspace/pbuilder/1173859/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/1173859/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/python-rx-4.0.4/ && 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  > ../python-rx_4.0.4-3_source.changes
 dpkg-buildpackage: info: source package python-rx
 dpkg-buildpackage: info: source version 4.0.4-3
 dpkg-buildpackage: info: source distribution unstable
@@ -1253,20 +1289,20 @@
 tests/test_observable/test_zip.py: 87 warnings
 tests/test_observable/test_blocking/test_blocking.py: 300 warnings
 tests/test_scheduler/test_currentthreadscheduler.py: 92 warnings
-tests/test_scheduler/test_eventloopscheduler.py: 85 warnings
+tests/test_scheduler/test_eventloopscheduler.py: 86 warnings
 tests/test_scheduler/test_immediatescheduler.py: 10 warnings
 tests/test_scheduler/test_newthreadscheduler.py: 49 warnings
 tests/test_scheduler/test_scheduleditem.py: 3 warnings
-tests/test_scheduler/test_threadpoolscheduler.py: 95 warnings
+tests/test_scheduler/test_threadpoolscheduler.py: 93 warnings
 tests/test_scheduler/test_timeoutscheduler.py: 74 warnings
 tests/test_scheduler/test_trampolinescheduler.py: 145 warnings
 tests/test_scheduler/test_eventloop/test_asyncioscheduler.py: 28 warnings
 tests/test_scheduler/test_eventloop/test_asynciothreadsafescheduler.py: 54 warnings
-tests/test_subject/test_asyncsubject.py: 77 warnings
-tests/test_subject/test_behaviorsubject.py: 81 warnings
+tests/test_subject/test_asyncsubject.py: 75 warnings
+tests/test_subject/test_behaviorsubject.py: 77 warnings
 tests/test_subject/test_replaysubject.py: 108 warnings
-tests/test_subject/test_subject.py: 60 warnings
-tests/test_testing/test_marbles.py: 32 warnings
+tests/test_subject/test_subject.py: 62 warnings
+tests/test_testing/test_marbles.py: 30 warnings
   /build/reproducible-path/python-rx-4.0.4/.pybuild/cpython3_3.12_rx/build/reactivex/internal/basic.py:17: DeprecationWarning: datetime.datetime.utcnow() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.now(datetime.UTC).
     return datetime.utcnow()
 
@@ -1403,7 +1439,7 @@
     return self.run(*args, **kwds)
 
 -- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
-============== 1324 passed, 10 skipped, 192611 warnings in 24.69s ==============
+============== 1324 passed, 10 skipped, 192604 warnings in 27.33s ==============
 I: pybuild base:311: cd /build/reproducible-path/python-rx-4.0.4/.pybuild/cpython3_3.11_rx/build; python3.11 -m pytest tests
 ============================= test session starts ==============================
 platform linux -- Python 3.11.8, pytest-7.4.4, pluggy-1.5.0
@@ -1580,7 +1616,7 @@
     return self.run(*args, **kwds)
 
 -- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
-================ 1324 passed, 10 skipped, 3 warnings in 21.94s =================
+================ 1324 passed, 10 skipped, 3 warnings in 21.61s =================
    create-stamp debian/debhelper-build-stamp
    dh_testroot -O--buildsystem=pybuild
    dh_prep -O--buildsystem=pybuild
@@ -1615,12 +1651,14 @@
 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/1173859/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/1173859/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/269398 and its subdirectories
-I: Current time: Sat May 31 00:38:52 -12 2025
-I: pbuilder-time-stamp: 1748695132
+I: removing directory /srv/workspace/pbuilder/1173859 and its subdirectories
+I: Current time: Sun Apr 28 20:18:30 +14 2024
+I: pbuilder-time-stamp: 1714285110