Diff of the two buildlogs:

--
--- b1/build.log	2025-01-26 16:53:57.351454263 +0000
+++ b2/build.log	2025-01-26 16:54:54.752845325 +0000
@@ -1,7 +1,6 @@
-W: cgroups are not available on the host, not using them.
 I: pbuilder: network access will be disabled during build
-I: Current time: Sat Feb 28 11:15:50 -12 2026
-I: pbuilder-time-stamp: 1772320550
+I: Current time: Mon Jan 27 06:54:00 +14 2025
+I: pbuilder-time-stamp: 1737910440
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/unstable-reproducible-base.tgz]
 I: copying local configuration
@@ -23,51 +22,84 @@
 dpkg-source: info: unpacking golang-github-mattn-go-xmpp_0.2.10-1.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/3296166/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/199624/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 Jan 26 16:54 /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/199624/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/199624/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]="37" [3]="1" [4]="release" [5]="aarch64-unknown-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=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=' 	
   '
-  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='3296166'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=0c84382e4c0a408d9cdd86e3c0351d66
+  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=199624
   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.nLQOnD1n/pbuilderrc_vMcL --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.nLQOnD1n/b1 --logfile b1/build.log golang-github-mattn-go-xmpp_0.2.10-1.dsc'
-  SUDO_GID='109'
-  SUDO_UID='104'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  _='/usr/sbin/chroot'
-  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.nLQOnD1n/pbuilderrc_Lpmk --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.nLQOnD1n/b2 --logfile b2/build.log golang-github-mattn-go-xmpp_0.2.10-1.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 codethink03-arm64 6.1.0-30-cloud-arm64 #1 SMP Debian 6.1.124-1 (2025-01-12) aarch64 GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-30-cloud-arm64 #1 SMP Debian 6.1.124-1 (2025-01-12) aarch64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Nov 22  2024 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/3296166/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Nov 22 14:40 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/199624/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -152,7 +184,7 @@
 Get: 39 http://deb.debian.org/debian unstable/main arm64 golang-golang-x-text-dev all 0.16.0-1 [4003 kB]
 Get: 40 http://deb.debian.org/debian unstable/main arm64 golang-golang-x-crypto-dev all 1:0.25.0-1 [1682 kB]
 Get: 41 http://deb.debian.org/debian unstable/main arm64 golang-golang-x-net-dev all 1:0.27.0-1 [898 kB]
-Fetched 69.8 MB in 0s (157 MB/s)
+Fetched 69.8 MB in 0s (244 MB/s)
 Preconfiguring packages ...
 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 ... 19946 files and directories currently installed.)
@@ -331,7 +363,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/golang-github-mattn-go-xmpp-0.2.10/ && 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-mattn-go-xmpp_0.2.10-1_source.changes
+I: user script /srv/workspace/pbuilder/199624/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for unstable
+I: user script /srv/workspace/pbuilder/199624/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/golang-github-mattn-go-xmpp-0.2.10/ && 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-mattn-go-xmpp_0.2.10-1_source.changes
 dpkg-buildpackage: info: source package golang-github-mattn-go-xmpp
 dpkg-buildpackage: info: source version 0.2.10-1
 dpkg-buildpackage: info: source distribution unstable
@@ -350,33 +386,33 @@
    dh_auto_configure -O--builddirectory=_build -O--buildsystem=golang
    dh_auto_build -O--builddirectory=_build -O--buildsystem=golang
 	cd _build && go install -trimpath -v -p 12 github.com/xmppo/go-xmpp
+internal/goarch
+internal/byteorder
+internal/godebugs
 internal/coverage/rtcov
-internal/goos
 internal/unsafeheader
-internal/godebugs
-internal/goarch
+internal/profilerecord
 internal/goexperiment
-unicode
-internal/runtime/syscall
-unicode/utf8
-math/bits
+sync/atomic
 internal/cpu
 internal/race
-internal/profilerecord
 internal/abi
-runtime/internal/sys
-sync/atomic
-internal/byteorder
+internal/goos
+unicode/utf8
+runtime/internal/math
+unicode
+internal/chacha8rand
+internal/runtime/syscall
+math/bits
 crypto/internal/alias
 crypto/subtle
 crypto/internal/boring/sig
+runtime/internal/sys
 internal/asan
-runtime/internal/math
 internal/itoa
-internal/chacha8rand
+math
 internal/msan
 cmp
-math
 container/list
 unicode/utf16
 vendor/golang.org/x/crypto/cryptobyte/asn1
@@ -384,78 +420,78 @@
 internal/nettrace
 encoding
 log/internal
-internal/bytealg
 internal/runtime/atomic
+internal/bytealg
 internal/runtime/exithook
 internal/stringslite
 runtime
 internal/reflectlite
-sync
 iter
 internal/weak
+sync
 slices
 maps
 internal/bisect
-internal/testlog
 internal/singleflight
+internal/testlog
 runtime/cgo
 errors
-internal/godebug
 sort
 io
+math/rand/v2
+path
+crypto/internal/nistec/fiat
 strconv
 internal/oserror
-path
-math/rand
-bytes
-math/rand/v2
 crypto/internal/edwards25519/field
-crypto/internal/nistec/fiat
+internal/godebug
 vendor/golang.org/x/net/dns/dnsmessage
+bytes
+strings
+math/rand
 crypto/internal/randutil
-hash
 crypto/internal/edwards25519
-internal/concurrent
-strings
 syscall
+internal/concurrent
+hash
 unique
 hash/crc32
+crypto/cipher
 crypto
-crypto/rc4
 reflect
+bufio
 crypto/md5
-crypto/cipher
+crypto/rc4
+net/netip
 vendor/golang.org/x/text/transform
-bufio
 net/http/internal/ascii
 regexp/syntax
 crypto/internal/boring
 crypto/des
 crypto/hmac
 crypto/sha1
-crypto/sha256
 crypto/sha512
 crypto/aes
+crypto/sha256
 vendor/golang.org/x/crypto/hkdf
-net/netip
 golang.org/x/crypto/pbkdf2
+regexp
+internal/syscall/execenv
 internal/syscall/unix
 time
-internal/syscall/execenv
-regexp
 internal/fmtsort
 encoding/binary
+context
 io/fs
 internal/poll
-context
 internal/filepathlite
 embed
 vendor/golang.org/x/crypto/chacha20
 vendor/golang.org/x/crypto/internal/poly1305
 encoding/base64
 crypto/internal/nistec
-encoding/pem
 os
+encoding/pem
 vendor/golang.org/x/crypto/chacha20poly1305
 crypto/ecdh
 fmt
@@ -464,26 +500,26 @@
 net
 vendor/golang.org/x/crypto/sha3
 math/big
+mime/quotedprintable
+vendor/golang.org/x/text/unicode/norm
+net/http/internal
 encoding/hex
 net/url
 encoding/xml
-compress/flate
 log
-vendor/golang.org/x/text/unicode/norm
+compress/flate
 vendor/golang.org/x/net/http2/hpack
 mime
-mime/quotedprintable
-net/http/internal
 vendor/golang.org/x/text/unicode/bidi
 compress/gzip
 vendor/golang.org/x/text/secure/bidirule
 vendor/golang.org/x/net/idna
-crypto/rand
-crypto/elliptic
 crypto/internal/bigmod
 crypto/internal/boring/bbig
 encoding/asn1
 crypto/dsa
+crypto/rand
+crypto/elliptic
 crypto/ed25519
 crypto/internal/hpke
 crypto/internal/mlkem768
@@ -491,10 +527,10 @@
 vendor/golang.org/x/crypto/cryptobyte
 crypto/x509/pkix
 crypto/ecdsa
-crypto/x509
 golang.org/x/net/internal/socks
-net/textproto
 vendor/golang.org/x/net/http/httpproxy
+net/textproto
+crypto/x509
 golang.org/x/net/proxy
 vendor/golang.org/x/net/http/httpguts
 mime/multipart
@@ -511,7 +547,7 @@
 === RUN   TestEmptyPubsub
 --- PASS: TestEmptyPubsub (0.00s)
 PASS
-ok  	github.com/xmppo/go-xmpp	0.016s
+ok  	github.com/xmppo/go-xmpp	0.010s
    create-stamp debian/debhelper-build-stamp
    dh_testroot -O--builddirectory=_build -O--buildsystem=golang
    dh_prep -O--builddirectory=_build -O--buildsystem=golang
@@ -538,12 +574,14 @@
 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/199624/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/199624/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/3296166 and its subdirectories
-I: Current time: Sat Feb 28 11:16:55 -12 2026
-I: pbuilder-time-stamp: 1772320615
+I: removing directory /srv/workspace/pbuilder/199624 and its subdirectories
+I: Current time: Mon Jan 27 06:54:53 +14 2025
+I: pbuilder-time-stamp: 1737910493