Diff of the two buildlogs:

--
--- b1/build.log	2023-06-09 18:45:17.132081212 +0000
+++ b2/build.log	2023-06-09 18:46:24.901116172 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Fri Jun  9 06:43:31 -12 2023
-I: pbuilder-time-stamp: 1686336211
+I: Current time: Fri Jul 12 15:08:10 +14 2024
+I: pbuilder-time-stamp: 1720746490
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/bookworm-reproducible-base.tgz]
 I: copying local configuration
@@ -16,7 +16,7 @@
 I: copying [./golang-github-jackpal-go-nat-pmp_1.0.2.orig.tar.gz]
 I: copying [./golang-github-jackpal-go-nat-pmp_1.0.2-3.debian.tar.xz]
 I: Extracting source
-gpgv: Signature made Wed Nov 23 11:05:24 2022 -12
+gpgv: Signature made Thu Nov 24 13:05:24 2022 +14
 gpgv:                using RSA key B23862C415D6565A4E86CBD7579C160D4C9E23E8
 gpgv: Can't check signature: No public key
 dpkg-source: warning: cannot verify inline signature for ./golang-github-jackpal-go-nat-pmp_1.0.2-3.dsc: no acceptable signature found
@@ -25,52 +25,84 @@
 dpkg-source: info: unpacking golang-github-jackpal-go-nat-pmp_1.0.2-3.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/16241/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/26325/tmp/hooks/D01_modify_environment starting
+debug: Running on codethink11-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 Jul 12 15:08 /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/26325/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/26325/tmp/hooks/D02_print_environment starting
 I: set
-  BUILDDIR='/build'
-  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]="15" [3]="1" [4]="release" [5]="aarch64-unknown-linux-gnu")
+  BASH_VERSION='5.2.15(1)-release'
+  BUILDDIR=/build
+  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=8 '
-  DISTRIBUTION='bookworm'
-  HOME='/var/lib/jenkins'
-  HOST_ARCH='arm64'
+  DIRSTACK=()
+  DISTRIBUTION=bookworm
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/var/lib/jenkins
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=aarch64
+  HOST_ARCH=arm64
   IFS=' 	
   '
-  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='16241'
-  PS1='# '
-  PS2='> '
+  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=26325
   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.KBJsDm30/pbuilderrc_beXw --distribution bookworm --hookdir /etc/pbuilder/first-build-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/bookworm-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.KBJsDm30/b1 --logfile b1/build.log golang-github-jackpal-go-nat-pmp_1.0.2-3.dsc'
-  SUDO_GID='117'
-  SUDO_UID='110'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  USERNAME='root'
-  _='/usr/bin/systemd-run'
-  http_proxy='http://192.168.101.16:3128'
+  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.KBJsDm30/pbuilderrc_2HbF --distribution bookworm --hookdir /etc/pbuilder/rebuild-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/bookworm-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.KBJsDm30/b2 --logfile b2/build.log --extrapackages usrmerge golang-github-jackpal-go-nat-pmp_1.0.2-3.dsc'
+  SUDO_GID=117
+  SUDO_UID=110
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  USERNAME=root
+  _='I: set'
+  http_proxy=http://192.168.101.16:3128
 I: uname -a
-  Linux codethink14-arm64 4.15.0-212-generic #223-Ubuntu SMP Tue May 23 13:09:17 UTC 2023 aarch64 GNU/Linux
+  Linux i-capture-the-hostname 4.15.0-212-generic #223-Ubuntu SMP Tue May 23 13:09:17 UTC 2023 aarch64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Jun  6 22:24 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/16241/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Jul 10 06:47 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/26325/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -146,7 +178,7 @@
 Get: 34 http://deb.debian.org/debian bookworm/main arm64 golang-src all 2:1.19~1 [5756 B]
 Get: 35 http://deb.debian.org/debian bookworm/main arm64 golang-go arm64 2:1.19~1 [45.0 kB]
 Get: 36 http://deb.debian.org/debian bookworm/main arm64 golang-any arm64 2:1.19~1 [5876 B]
-Fetched 93.3 MB in 4s (24.5 MB/s)
+Fetched 93.3 MB in 1s (62.3 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 ... 19611 files and directories currently installed.)
@@ -304,8 +336,17 @@
 Writing extended state information...
 Building tag database...
  -> Finished parsing the build-deps
+Reading package lists...
+Building dependency tree...
+Reading state information...
+usrmerge is already the newest version (35).
+0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
 I: Building the package
-I: Running cd /build/golang-github-jackpal-go-nat-pmp-1.0.2/ && 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-jackpal-go-nat-pmp_1.0.2-3_source.changes
+I: user script /srv/workspace/pbuilder/26325/tmp/hooks/A99_set_merged_usr starting
+Re-configuring usrmerge...
+I: user script /srv/workspace/pbuilder/26325/tmp/hooks/A99_set_merged_usr finished
+hostname: Temporary failure in name resolution
+I: Running cd /build/golang-github-jackpal-go-nat-pmp-1.0.2/ && 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-jackpal-go-nat-pmp_1.0.2-3_source.changes
 dpkg-buildpackage: info: source package golang-github-jackpal-go-nat-pmp
 dpkg-buildpackage: info: source version 1.0.2-3
 dpkg-buildpackage: info: source distribution unstable
@@ -325,24 +366,24 @@
    dh_auto_build -O--builddirectory=_build -O--buildsystem=golang
 	cd _build && go install -trimpath -v -p 8 github.com/jackpal/go-nat-pmp
 internal/goarch
-internal/unsafeheader
 internal/goexperiment
-internal/goos
-math/bits
 internal/itoa
+internal/unsafeheader
+math/bits
 internal/cpu
-runtime/internal/math
+internal/goos
+unicode/utf8
+internal/race
 runtime/internal/syscall
 internal/abi
+runtime/internal/math
 runtime/internal/sys
-unicode/utf8
-internal/race
 sync/atomic
 unicode
 internal/nettrace
-internal/bytealg
-runtime/internal/atomic
 math
+runtime/internal/atomic
+internal/bytealg
 runtime
 internal/reflectlite
 sync
@@ -351,8 +392,8 @@
 runtime/cgo
 errors
 sort
-io
 internal/oserror
+io
 internal/safefilepath
 path
 vendor/golang.org/x/net/dns/dnsmessage
@@ -362,9 +403,9 @@
 internal/syscall/unix
 internal/syscall/execenv
 time
-internal/poll
 context
 io/fs
+internal/poll
 os
 internal/fmtsort
 internal/godebug
@@ -393,7 +434,7 @@
     natpmp_test.go:238: case 3
 --- PASS: TestProtocolChecks (0.00s)
 PASS
-ok  	github.com/jackpal/go-nat-pmp	0.036s
+ok  	github.com/jackpal/go-nat-pmp	0.005s
    create-stamp debian/debhelper-build-stamp
    dh_testroot -O--builddirectory=_build -O--buildsystem=golang
    dh_prep -O--builddirectory=_build -O--buildsystem=golang
@@ -421,12 +462,14 @@
 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/26325/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/26325/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/16241 and its subdirectories
-I: Current time: Fri Jun  9 06:45:16 -12 2023
-I: pbuilder-time-stamp: 1686336316
+I: removing directory /srv/workspace/pbuilder/26325 and its subdirectories
+I: Current time: Fri Jul 12 15:09:14 +14 2024
+I: pbuilder-time-stamp: 1720746554