Diff of the two buildlogs:

--
--- b1/build.log	2024-05-13 02:31:57.245867571 +0000
+++ b2/build.log	2024-05-13 02:33:04.407009455 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sat Jun 14 20:54:12 -12 2025
-I: pbuilder-time-stamp: 1749977652
+I: Current time: Mon May 13 16:32:00 +14 2024
+I: pbuilder-time-stamp: 1715567520
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/unstable-reproducible-base.tgz]
 I: copying local configuration
@@ -25,52 +25,84 @@
 dpkg-source: info: unpacking golang-github-pborman-uuid_1.2.0-2.debian.tar.xz
 I: using fakeroot in build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/91176/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/3468680/tmp/hooks/D01_modify_environment starting
+debug: Running on codethink04-arm64.
+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 May 13 02:32 /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/3468680/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/3468680/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='arm64'
-  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]="aarch64-unknown-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=arm64
+  DEBIAN_FRONTEND=noninteractive
   DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=12 '
-  DISTRIBUTION='unstable'
-  HOME='/root'
-  HOST_ARCH='arm64'
+  DIRSTACK=()
+  DISTRIBUTION=unstable
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=aarch64
+  HOST_ARCH=arm64
   IFS=' 	
   '
-  INVOCATION_ID='e114a0f839fe45aaa253fc45870d6cdb'
-  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='91176'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=d9039cefc54742f1afa24469decb314a
+  LANG=C
+  LANGUAGE=nl_BE:nl
+  LC_ALL=C
+  MACHTYPE=aarch64-unknown-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=3468680
   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.wRmWUJRN/pbuilderrc_9Xf9 --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.wRmWUJRN/b1 --logfile b1/build.log golang-github-pborman-uuid_1.2.0-2.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'
-  http_proxy='http://192.168.101.4:3128'
+  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.wRmWUJRN/pbuilderrc_LRD6 --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.wRmWUJRN/b2 --logfile b2/build.log golang-github-pborman-uuid_1.2.0-2.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'
+  http_proxy=http://192.168.101.4:3128
 I: uname -a
-  Linux codethink01-arm64 6.1.0-21-cloud-arm64 #1 SMP Debian 6.1.90-1 (2024-05-03) aarch64 GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-21-cloud-arm64 #1 SMP Debian 6.1.90-1 (2024-05-03) aarch64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Jun 13 14:05 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/91176/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 May 11 07:44 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/3468680/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -149,7 +181,7 @@
 Get: 35 http://deb.debian.org/debian unstable/main arm64 golang-go arm64 2:1.22~3 [44.2 kB]
 Get: 36 http://deb.debian.org/debian unstable/main arm64 golang-any arm64 2:1.22~3 [5104 B]
 Get: 37 http://deb.debian.org/debian unstable/main arm64 golang-github-google-uuid-dev all 1.6.0-1 [20.6 kB]
-Fetched 58.9 MB in 0s (211 MB/s)
+Fetched 58.9 MB in 0s (177 MB/s)
 debconf: delaying package configuration, since apt-utils is not installed
 Selecting previously unselected package sensible-utils.
 (Reading database ... 
(Reading database ... 5%
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(Reading database ... 100%
(Reading database ... 19744 files and directories currently installed.)
@@ -317,7 +349,11 @@
 fakeroot is already the newest version (1.34-1).
 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
 I: Building the package
-I: Running cd /build/reproducible-path/golang-github-pborman-uuid-1.2.0/ && 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  > ../golang-github-pborman-uuid_1.2.0-2_source.changes
+I: user script /srv/workspace/pbuilder/3468680/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for unstable
+I: user script /srv/workspace/pbuilder/3468680/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/golang-github-pborman-uuid-1.2.0/ && 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  > ../golang-github-pborman-uuid_1.2.0-2_source.changes
 dpkg-buildpackage: info: source package golang-github-pborman-uuid
 dpkg-buildpackage: info: source version 1.2.0-2
 dpkg-buildpackage: info: source distribution unstable
@@ -337,35 +373,35 @@
    dh_auto_configure -O--buildsystem=golang
    dh_auto_build -O--buildsystem=golang
 	cd obj-aarch64-linux-gnu && go install -trimpath -v -p 12 github.com/pborman/uuid
-internal/goos
 internal/coverage/rtcov
 internal/unsafeheader
-internal/goarch
 internal/godebugs
 internal/goexperiment
-runtime/internal/syscall
-internal/race
+unicode
+math/bits
 unicode/utf8
+internal/goos
 internal/cpu
-sync/atomic
-math/bits
+internal/goarch
 internal/itoa
-unicode
-internal/abi
-internal/chacha8rand
-runtime/internal/math
-runtime/internal/sys
+runtime/internal/syscall
+internal/race
+sync/atomic
 crypto/internal/alias
 crypto/subtle
 crypto/internal/boring/sig
 cmp
+internal/abi
+internal/chacha8rand
+runtime/internal/math
+runtime/internal/sys
 encoding
-unicode/utf16
-internal/nettrace
 slices
-internal/bytealg
 math
+unicode/utf16
+internal/nettrace
 runtime/internal/atomic
+internal/bytealg
 runtime
 internal/reflectlite
 sync
@@ -373,45 +409,45 @@
 internal/bisect
 internal/singleflight
 runtime/cgo
+internal/godebug
 errors
 sort
-internal/oserror
-io
+internal/intern
+math/rand
 internal/safefilepath
-strconv
-path
-internal/godebug
 vendor/golang.org/x/net/dns/dnsmessage
-hash
+path
+strconv
+io
+internal/oserror
+syscall
 bytes
+hash
 crypto/internal/randutil
-syscall
-internal/intern
-crypto
-math/rand
-reflect
 strings
+crypto
 net/netip
-internal/syscall/execenv
+reflect
 internal/syscall/unix
 time
-internal/fmtsort
+internal/syscall/execenv
 encoding/binary
-context
-io/fs
+internal/fmtsort
 internal/poll
+io/fs
+context
 crypto/md5
-encoding/base64
 crypto/cipher
-os
+encoding/base64
 crypto/internal/boring
+os
 crypto/sha1
 fmt
 net
+math/big
 database/sql/driver
 encoding/hex
 encoding/json
-math/big
 crypto/rand
 github.com/google/uuid
 github.com/pborman/uuid
@@ -462,7 +498,7 @@
 === RUN   TestArray_UUID
 --- PASS: TestArray_UUID (0.00s)
 PASS
-ok  	github.com/pborman/uuid	0.011s
+ok  	github.com/pborman/uuid	0.047s
 make[1]: Leaving directory '/build/reproducible-path/golang-github-pborman-uuid-1.2.0'
    create-stamp debian/debhelper-build-stamp
  fakeroot debian/rules binary
@@ -495,12 +531,14 @@
 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/3468680/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/3468680/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/91176 and its subdirectories
-I: Current time: Sat Jun 14 20:54:55 -12 2025
-I: pbuilder-time-stamp: 1749977695
+I: removing directory /srv/workspace/pbuilder/3468680 and its subdirectories
+I: Current time: Mon May 13 16:33:03 +14 2024
+I: pbuilder-time-stamp: 1715567583