Diff of the two buildlogs:

--
--- b1/build.log	2024-01-14 00:20:17.449200348 +0000
+++ b2/build.log	2024-01-14 00:25:16.737963039 +0000
@@ -1,6 +1,9 @@
-I: pbuilder: network access will be disabled during build
-I: Current time: Fri Feb 14 18:42:41 -12 2025
-I: pbuilder-time-stamp: 1739601761
+W: cgroups are not available on the host, not using them.
+unshare: unshare failed: Cannot allocate memory
+W: pbuilder: unshare CLONE_NEWNET not available
+I: pbuilder: network access is available during build!
+I: Current time: Sun Jan 14 14:24:20 +14 2024
+I: pbuilder-time-stamp: 1705191860
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/bullseye-reproducible-base.tgz]
 I: copying local configuration
@@ -17,7 +20,7 @@
 I: copying [./debian-parl_1.9.27+deb11u1.tar.xz]
 I: Extracting source
 gpgv: unknown type of key resource 'trustedkeys.kbx'
-gpgv: keyblock resource '/tmp/dpkg-verify-sig.W4cdHBEC/trustedkeys.kbx': General error
+gpgv: keyblock resource '/tmp/dpkg-verify-sig.niXcLPNK/trustedkeys.kbx': General error
 gpgv: Signature made Wed Jun 28 12:49:12 2023 
 gpgv:                using RSA key EBF30A30A8D9C63BDA44C6945FB33F9359E9ED08
 gpgv:                issuer "anbe@debian.org"
@@ -27,51 +30,81 @@
 dpkg-source: info: unpacking debian-parl_1.9.27+deb11u1.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/37616/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/22479/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 Jan 14 00:24 /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/22479/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/22479/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,-fixfilepath parallel=16 '
-  DISTRIBUTION='bullseye'
-  HOME='/root'
-  HOST_ARCH='i386'
+  BASH=/bin/sh
+  BASHOPTS=checkwinsize:cmdhist:complete_fullquote:extquote:force_fignore:globasciiranges:hostcomplete:interactive_comments:progcomp:promptvars:sourcepath
+  BASH_ALIASES=()
+  BASH_ARGC=()
+  BASH_ARGV=()
+  BASH_CMDS=()
+  BASH_LINENO=([0]="12" [1]="0")
+  BASH_SOURCE=([0]="/tmp/hooks/D02_print_environment" [1]="/tmp/hooks/D02_print_environment")
+  BASH_VERSINFO=([0]="5" [1]="1" [2]="4" [3]="1" [4]="release" [5]="i686-pc-linux-gnu")
+  BASH_VERSION='5.1.4(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,-fixfilepath parallel=7 '
+  DIRSTACK=()
+  DISTRIBUTION=bullseye
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=i686
+  HOST_ARCH=i386
   IFS=' 	
   '
-  INVOCATION_ID='69c5379eb770465ebd2ec3ac69eae60d'
-  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='37616'
-  PS1='# '
-  PS2='> '
+  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=22479
   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.Wc54giCe/pbuilderrc_GQG6 --distribution bullseye --hookdir /etc/pbuilder/first-build-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/bullseye-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.Wc54giCe/b1 --logfile b1/build.log debian-parl_1.9.27+deb11u1.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.Wc54giCe/pbuilderrc_7LE8 --distribution bullseye --hookdir /etc/pbuilder/rebuild-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/bullseye-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.Wc54giCe/b2 --logfile b2/build.log debian-parl_1.9.27+deb11u1.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 ionos16-i386 6.1.0-17-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.69-1 (2023-12-30) x86_64 GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-17-686-pae #1 SMP PREEMPT_DYNAMIC Debian 6.1.69-1 (2023-12-30) i686 GNU/Linux
 I: ls -l /bin
   total 5776
   -rwxr-xr-x 1 root root 1367848 Mar 27  2022 bash
@@ -131,7 +164,7 @@
   -rwxr-xr-x 1 root root   46984 Sep 22  2020 rmdir
   -rwxr-xr-x 1 root root   22292 Sep 27  2020 run-parts
   -rwxr-xr-x 1 root root  125036 Dec 22  2018 sed
-  lrwxrwxrwx 1 root root       4 Feb  8 15:47 sh -> dash
+  lrwxrwxrwx 1 root root       9 Jan 14 00:24 sh -> /bin/bash
   -rwxr-xr-x 1 root root   34696 Sep 22  2020 sleep
   -rwxr-xr-x 1 root root   83880 Sep 22  2020 stty
   -rwsr-xr-x 1 root root   79396 Jan 20  2022 su
@@ -157,7 +190,7 @@
   -rwxr-xr-x 1 root root    2206 Apr 10  2022 zless
   -rwxr-xr-x 1 root root    1842 Apr 10  2022 zmore
   -rwxr-xr-x 1 root root    4577 Apr 10  2022 znew
-I: user script /srv/workspace/pbuilder/37616/tmp/hooks/D02_print_environment finished
+I: user script /srv/workspace/pbuilder/22479/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -297,7 +330,7 @@
 Get: 92 http://deb.debian.org/debian bullseye/main i386 po-debconf all 1.0.21+nmu1 [248 kB]
 Get: 93 http://deb.debian.org/debian bullseye/main i386 debhelper all 13.3.4 [1049 kB]
 Get: 94 http://deb.debian.org/debian bullseye/main i386 shellcheck i386 0.7.1-1+deb11u1 [2101 kB]
-Fetched 22.8 MB in 1s (22.7 MB/s)
+Fetched 22.8 MB in 2s (12.6 MB/s)
 debconf: delaying package configuration, since apt-utils is not installed
 Selecting previously unselected package bsdextrautils.
 (Reading database ... 
(Reading database ... 5%
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(Reading database ... 20%
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(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 ... 17763 files and directories currently installed.)
@@ -689,7 +722,10 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/debian-parl-1.9.27+deb11u1/ && 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  > ../debian-parl_1.9.27+deb11u1_source.changes
+I: user script /srv/workspace/pbuilder/22479/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for bullseye
+I: user script /srv/workspace/pbuilder/22479/tmp/hooks/A99_set_merged_usr finished
+I: Running cd /build/reproducible-path/debian-parl-1.9.27+deb11u1/ && 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  > ../debian-parl_1.9.27+deb11u1_source.changes
 dpkg-buildpackage: info: source package debian-parl
 dpkg-buildpackage: info: source version 1.9.27+deb11u1
 dpkg-buildpackage: info: source distribution bullseye
@@ -1025,13 +1061,14 @@
  dpkg-source --after-build .
 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/22479/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/22479/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/37616 and its subdirectories
-I: Current time: Fri Feb 14 18:43:14 -12 2025
-I: pbuilder-time-stamp: 1739601794
+I: removing directory /srv/workspace/pbuilder/22479 and its subdirectories
+I: Current time: Sun Jan 14 14:25:13 +14 2024
+I: pbuilder-time-stamp: 1705191913