Diff of the two buildlogs:

--
--- b1/build.log	2025-03-15 07:48:25.153146358 +0000
+++ b2/build.log	2025-03-15 07:49:49.329363684 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Fri Mar 14 19:45:42 -12 2025
-I: pbuilder-time-stamp: 1742024742
+I: Current time: Sat Apr 18 04:11:27 +14 2026
+I: pbuilder-time-stamp: 1776435087
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/unstable-reproducible-base.tgz]
 I: copying local configuration
@@ -24,52 +24,84 @@
 dpkg-source: info: applying makefile-bashism-pr4147
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/1339016/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/1235245/tmp/hooks/D01_modify_environment starting
+debug: Running on ionos15-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 14:11 /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/1235245/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/1235245/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'
-  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=20 '
-  DISTRIBUTION='unstable'
-  HOME='/root'
-  HOST_ARCH='amd64'
+  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=42 '
+  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='eda5bcc4d77f4a54835d2c20edd715a6'
-  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='1339016'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=12a39eec68b34410b28e9c1ca4313859
+  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=1235245
   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.rLuL7x6w/pbuilderrc_v8rt --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.rLuL7x6w/b1 --logfile b1/build.log librdkafka_2.8.0-1.dsc'
-  SUDO_GID='111'
-  SUDO_UID='106'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  _='/usr/bin/systemd-run'
-  http_proxy='http://46.16.76.132:3128'
+  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.rLuL7x6w/pbuilderrc_WIQ0 --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.rLuL7x6w/b2 --logfile b2/build.log librdkafka_2.8.0-1.dsc'
+  SUDO_GID=111
+  SUDO_UID=106
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  _='I: set'
+  http_proxy=http://213.165.73.152:3128
 I: uname -a
-  Linux ionos11-amd64 6.1.0-31-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/1339016/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Mar  4  2025 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/1235245/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -223,7 +255,7 @@
 Get: 98 http://deb.debian.org/debian unstable/main amd64 liblz4-dev amd64 1.10.0-4 [88.4 kB]
 Get: 99 http://deb.debian.org/debian unstable/main amd64 libsasl2-dev amd64 2.1.28+dfsg1-9 [234 kB]
 Get: 100 http://deb.debian.org/debian unstable/main amd64 rapidjson-dev all 1.1.0+dfsg2-7.3 [98.0 kB]
-Fetched 44.2 MB in 8s (5249 kB/s)
+Fetched 44.2 MB in 4s (10.4 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.)
@@ -559,8 +591,8 @@
 Setting up tzdata (2025a-2) ...
 
 Current default time zone: 'Etc/UTC'
-Local time is now:      Sat Mar 15 07:47:02 UTC 2025.
-Universal Time is now:  Sat Mar 15 07:47:02 UTC 2025.
+Local time is now:      Fri Apr 17 14:12:12 UTC 2026.
+Universal Time is now:  Fri Apr 17 14:12:12 UTC 2026.
 Run 'dpkg-reconfigure tzdata' if you wish to change it.
 
 Setting up autotools-dev (20220109.1) ...
@@ -650,7 +682,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/librdkafka-2.8.0/ && 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  > ../librdkafka_2.8.0-1_source.changes
+I: user script /srv/workspace/pbuilder/1235245/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for unstable
+I: user script /srv/workspace/pbuilder/1235245/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/librdkafka-2.8.0/ && 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  > ../librdkafka_2.8.0-1_source.changes
 dpkg-buildpackage: info: source package librdkafka
 dpkg-buildpackage: info: source version 2.8.0-1
 dpkg-buildpackage: info: source distribution unstable
@@ -660,7 +696,7 @@
  debian/rules clean
 dh clean
    dh_auto_clean
-	make -j20 distclean
+	make -j42 distclean
 make[1]: Entering directory '/build/reproducible-path/librdkafka-2.8.0'
 rm -rf "mklove//deps"
 make[2]: Entering directory '/build/reproducible-path/librdkafka-2.8.0/tests'
@@ -811,7 +847,7 @@
 
 Now type 'make' to build
    dh_auto_build
-	make -j20
+	make -j42
 make[1]: Entering directory '/build/reproducible-path/librdkafka-2.8.0'
 make[2]: Entering directory '/build/reproducible-path/librdkafka-2.8.0/src'
 gcc -MD -MP -Wdate-time -D_FORTIFY_SOURCE=2 -Wdate-time -D_FORTIFY_SOURCE=2 -I/usr/include -g -O2 -fPIC -Wall -Wsign-compare -Wfloat-equal -Wpointer-arith -Wcast-align -Wdate-time -D_FORTIFY_SOURCE=2 -I/usr/include -g -O2 -fPIC -Wall -Wsign-compare -Wfloat-equal -Wpointer-arith -Wcast-align -I. -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/librdkafka-2.8.0=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/librdkafka-2.8.0=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection      -I/usr/include/x86_64-linux-gnu -isystem /usr/include/mit-krb5 -I/usr/include/p11-kit-1   -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/librdkafka-2.8.0=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection      -I/usr/include/x86_64-linux-gnu -isystem /usr/include/mit-krb5 -I/usr/include/p11-kit-1   -c rdkafka.c -o rdkafka.o
@@ -918,8 +954,8 @@
 WARNING: librdkafka-static.a: No static libraries available/enabled for inclusion in self-contained static library librdkafka-static.a: this library will be identical to librdkafka.a
 WARNING: librdkafka-static.a: The following libraries were not available as static libraries and need to be linked dynamically: -llz4 -lxxhash -lm -lcurl -lzstd -lsasl2 -lssl -lcrypto -lz -ldl -lpthread -lrt -lpthread -lrt
 cp librdkafka.a librdkafka-static.a
-cp librdkafka.so.1 librdkafka-dbg.so.1
 cp librdkafka-dbg.a librdkafka-static-dbg.a
+cp librdkafka.so.1 librdkafka-dbg.so.1
 Creating librdkafka.so symlink
 rm -f "librdkafka.so" && ln -s "librdkafka.so.1" "librdkafka.so"
 cp librdkafka-static.a librdkafka-static-dbg.a
@@ -1054,7 +1090,7 @@
 make[2]: Leaving directory '/build/reproducible-path/librdkafka-2.8.0/src-cpp'
 make[1]: Leaving directory '/build/reproducible-path/librdkafka-2.8.0'
    dh_auto_test
-	make -j20 check "TESTSUITEFLAGS=-j20 --verbose" VERBOSE=1
+	make -j42 check "TESTSUITEFLAGS=-j42 --verbose" VERBOSE=1
 make[1]: Entering directory '/build/reproducible-path/librdkafka-2.8.0'
 make[2]: Entering directory '/build/reproducible-path/librdkafka-2.8.0/src'
 Checking librdkafka integrity
@@ -1094,7 +1130,7 @@
    create-stamp debian/debhelper-build-stamp
    dh_prep
    dh_auto_install
-	make -j20 install DESTDIR=/build/reproducible-path/librdkafka-2.8.0/debian/tmp AM_UPDATE_INFO_DIR=no
+	make -j42 install DESTDIR=/build/reproducible-path/librdkafka-2.8.0/debian/tmp AM_UPDATE_INFO_DIR=no
 make[1]: Entering directory '/build/reproducible-path/librdkafka-2.8.0'
 make[2]: Entering directory '/build/reproducible-path/librdkafka-2.8.0/src'
 Checking librdkafka integrity
@@ -1114,14 +1150,14 @@
 make[2]: Nothing to be done for 'all'.
 make[2]: Leaving directory '/build/reproducible-path/librdkafka-2.8.0/examples'
 Updating CONFIGURATION.md
+Installing documentation to /build/reproducible-path/librdkafka-2.8.0/debian/tmp/usr
+/usr/bin/install -d $DESTDIR/usr/share/doc/librdkafka
+/usr/bin/install LICENSE LICENSES.txt INTRODUCTION.md README.md CONFIGURATION.md STATISTICS.md CHANGELOG.md $DESTDIR/usr/share/doc/librdkafka
 Install librdkafka to /build/reproducible-path/librdkafka-2.8.0/debian/tmp/usr
 /usr/bin/install -d $DESTDIR/usr/include/librdkafka
 /usr/bin/install -d $DESTDIR/usr/lib/x86_64-linux-gnu
 /usr/bin/install rdkafka.h rdkafka_mock.h $DESTDIR/usr/include/librdkafka
 /usr/bin/install librdkafka.a $DESTDIR/usr/lib/x86_64-linux-gnu
-Installing documentation to /build/reproducible-path/librdkafka-2.8.0/debian/tmp/usr
-/usr/bin/install -d $DESTDIR/usr/share/doc/librdkafka
-/usr/bin/install LICENSE LICENSES.txt INTRODUCTION.md README.md CONFIGURATION.md STATISTICS.md CHANGELOG.md $DESTDIR/usr/share/doc/librdkafka
 [ ! -f librdkafka-static.a ] || /usr/bin/install librdkafka-static.a $DESTDIR/usr/lib/x86_64-linux-gnu
 /usr/bin/install librdkafka.so.1 $DESTDIR/usr/lib/x86_64-linux-gnu
 [ -f "rdkafka.pc" ] && ( \
@@ -1175,11 +1211,11 @@
    dh_gencontrol
    dh_md5sums
    dh_builddeb
-dpkg-deb: building package 'librdkafka-dev' in '../librdkafka-dev_2.8.0-1_amd64.deb'.
 dpkg-deb: building package 'librdkafka1' in '../librdkafka1_2.8.0-1_amd64.deb'.
 dpkg-deb: building package 'librdkafka1-dbgsym' in '../librdkafka1-dbgsym_2.8.0-1_amd64.deb'.
 dpkg-deb: building package 'librdkafka++1' in '../librdkafka++1_2.8.0-1_amd64.deb'.
 dpkg-deb: building package 'librdkafka++1-dbgsym' in '../librdkafka++1-dbgsym_2.8.0-1_amd64.deb'.
+dpkg-deb: building package 'librdkafka-dev' in '../librdkafka-dev_2.8.0-1_amd64.deb'.
  dpkg-genbuildinfo --build=binary -O../librdkafka_2.8.0-1_amd64.buildinfo
  dpkg-genchanges --build=binary -O../librdkafka_2.8.0-1_amd64.changes
 dpkg-genchanges: info: binary-only upload (no source code included)
@@ -1187,12 +1223,14 @@
 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/1235245/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/1235245/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/1339016 and its subdirectories
-I: Current time: Fri Mar 14 19:48:24 -12 2025
-I: pbuilder-time-stamp: 1742024904
+I: removing directory /srv/workspace/pbuilder/1235245 and its subdirectories
+I: Current time: Sat Apr 18 04:12:48 +14 2026
+I: pbuilder-time-stamp: 1776435168