Diff of the two buildlogs:

--
--- b1/build.log	2024-10-31 07:34:30.811505108 +0000
+++ b2/build.log	2024-10-31 07:51:48.286536051 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Wed Oct 30 18:44:09 -12 2024
-I: pbuilder-time-stamp: 1730357049
+I: Current time: Thu Dec  4 03:57:32 +14 2025
+I: pbuilder-time-stamp: 1764770252
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/unstable-reproducible-base.tgz]
 I: copying local configuration
@@ -26,52 +26,84 @@
 dpkg-source: info: unpacking nim-lapper_0.1.7-5.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/3054742/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/3244530/tmp/hooks/D01_modify_environment starting
+debug: Running on ionos5-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 Dec  3 13:57 /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/3244530/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/3244530/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]="32" [3]="1" [4]="release" [5]="x86_64-pc-linux-gnu")
+  BASH_VERSION='5.2.32(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='9798a331533f4ad9b4faa03007420110'
-  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='3054742'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=52da8d4d311644d9af1079aebd045aed
+  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=3244530
   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.R9B1JEz8/pbuilderrc_Gtyj --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.R9B1JEz8/b1 --logfile b1/build.log nim-lapper_0.1.7-5.dsc'
-  SUDO_GID='110'
-  SUDO_UID='105'
-  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.R9B1JEz8/pbuilderrc_Pslh --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.R9B1JEz8/b2 --logfile b2/build.log nim-lapper_0.1.7-5.dsc'
+  SUDO_GID=110
+  SUDO_UID=105
+  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 ionos1-amd64 6.1.0-26-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.112-1 (2024-09-30) x86_64 GNU/Linux
+  Linux i-capture-the-hostname 6.10.11+bpo-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.10.11-1~bpo12+1 (2024-10-03) x86_64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Aug  4 21:30 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/3054742/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Aug  4  2024 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/3244530/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -140,7 +172,7 @@
 Get: 29 http://deb.debian.org/debian unstable/main amd64 debhelper all 13.20 [915 kB]
 Get: 30 http://deb.debian.org/debian unstable/main amd64 libpcre3 amd64 2:8.39-15.1 [346 kB]
 Get: 31 http://deb.debian.org/debian unstable/main amd64 nim amd64 1.6.14-3 [4164 kB]
-Fetched 24.3 MB in 3s (7315 kB/s)
+Fetched 24.3 MB in 0s (115 MB/s)
 debconf: delaying package configuration, since apt-utils is not installed
 Selecting previously unselected package sensible-utils.
 (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 ... 19969 files and directories currently installed.)
@@ -279,7 +311,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/nim-lapper-0.1.7/ && 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  > ../nim-lapper_0.1.7-5_source.changes
+I: user script /srv/workspace/pbuilder/3244530/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for unstable
+I: user script /srv/workspace/pbuilder/3244530/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/nim-lapper-0.1.7/ && 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  > ../nim-lapper_0.1.7-5_source.changes
 dpkg-buildpackage: info: source package nim-lapper
 dpkg-buildpackage: info: source version 0.1.7-5
 dpkg-buildpackage: info: source distribution unstable
@@ -324,17 +360,17 @@
 CC: lapper.nim
 Hint:  [Link]
 Hint: gc: refc; opt: speed; options: -d:release
-51353 lines; 7.373s; 75.496MiB peakmem; proj: src/lapper; out: /build/reproducible-path/nim-lapper-0.1.7/src/lapper [SuccessX]
+51353 lines; 3.286s; 75.461MiB peakmem; proj: src/lapper; out: /build/reproducible-path/nim-lapper-0.1.7/src/lapper [SuccessX]
 Hint: /build/reproducible-path/nim-lapper-0.1.7/src/lapper  [Exec]
 running tests and comparisons on 100000 random intervals
-time for brute force search on 1/10th of the data:7.887632366999999
-time to create Lapper:0.03935924600000007
-time to do 4000000 searches (40 reps) in Lapper:3.444201632 speedup:916.047689393813
-time to do 4000000 seek-searches (40 reps) in Lapper:1302.701795864 speedup:2.421930296570638
-time to do 4000000 presence tests (40 reps) in Lapper:2.471357686999909 speedup:1276.647635183096
-time to do 4000000 seek-presence tests (40 reps) in Lapper:1386.95700091 speedup:2.274802279183803
-time to do 4000000 each-seek-presence tests (40 reps) in Lapper:1.351891748000071 speedup:2333.805906772821
-time to check each result:51.25156669900025
+time for brute force search on 1/10th of the data:3.64959887
+time to create Lapper:0.02390410000000021
+time to do 4000000 searches (40 reps) in Lapper:2.152348849 speedup:678.2541541433927
+time to do 4000000 seek-searches (40 reps) in Lapper:488.642940897 speedup:2.987538396278022
+time to do 4000000 presence tests (40 reps) in Lapper:1.626759556000025 speedup:897.39110037229
+time to do 4000000 seek-presence tests (40 reps) in Lapper:489.673824516 speedup:2.981248894492011
+time to do 4000000 each-seek-presence tests (40 reps) in Lapper:0.9515730790000134 speedup:1534.132879772211
+time to check each result:11.93182407100005
 make[1]: Leaving directory '/build/reproducible-path/nim-lapper-0.1.7'
    create-stamp debian/debhelper-build-stamp
    dh_prep
@@ -361,12 +397,14 @@
 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/3244530/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/3244530/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/3054742 and its subdirectories
-I: Current time: Wed Oct 30 19:34:27 -12 2024
-I: pbuilder-time-stamp: 1730360067
+I: removing directory /srv/workspace/pbuilder/3244530 and its subdirectories
+I: Current time: Thu Dec  4 04:14:46 +14 2025
+I: pbuilder-time-stamp: 1764771286