Diff of the two buildlogs:

--
--- b1/build.log	2024-12-18 07:30:43.601574078 +0000
+++ b2/build.log	2024-12-18 07:33:45.909299023 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Tue Dec 17 19:28:59 -12 2024
-I: pbuilder-time-stamp: 1734506939
+I: Current time: Wed Dec 18 21:30:53 +14 2024
+I: pbuilder-time-stamp: 1734507053
 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-muesli-mango-pflag_0.1.0-1.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/25459/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/19578/tmp/hooks/D01_modify_environment starting
+debug: Running on ff4a.
+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 18 07:31 /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/19578/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/19578/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='armhf'
-  DEBIAN_FRONTEND='noninteractive'
-  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=3 '
-  DISTRIBUTION='unstable'
-  HOME='/root'
-  HOST_ARCH='armhf'
+  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]="arm-unknown-linux-gnueabihf")
+  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=armhf
+  DEBIAN_FRONTEND=noninteractive
+  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=4 '
+  DIRSTACK=()
+  DISTRIBUTION=unstable
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=arm
+  HOST_ARCH=armhf
   IFS=' 	
   '
-  INVOCATION_ID='03fa919fc5834628ba7a8e09f5ccf71f'
-  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='25459'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=77a04db5542745ef9301971d64652b5b
+  LANG=C
+  LANGUAGE=it_CH:it
+  LC_ALL=C
+  MACHTYPE=arm-unknown-linux-gnueabihf
+  MAIL=/var/mail/root
+  OPTERR=1
+  OPTIND=1
+  OSTYPE=linux-gnueabihf
+  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=19578
   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.jvA4ctPW/pbuilderrc_1oES --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.jvA4ctPW/b1 --logfile b1/build.log golang-github-muesli-mango-pflag_0.1.0-1.dsc'
-  SUDO_GID='110'
-  SUDO_UID='103'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  _='/usr/bin/systemd-run'
-  http_proxy='http://10.0.0.15:3142/'
+  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.jvA4ctPW/pbuilderrc_T7wu --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.jvA4ctPW/b2 --logfile b2/build.log golang-github-muesli-mango-pflag_0.1.0-1.dsc'
+  SUDO_GID=113
+  SUDO_UID=107
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  _='I: set'
+  http_proxy=http://10.0.0.15:3142/
 I: uname -a
-  Linux virt64z 6.1.0-28-arm64 #1 SMP Debian 6.1.119-1 (2024-11-22) aarch64 GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-28-armmp-lpae #1 SMP Debian 6.1.119-1 (2024-11-22) armv7l GNU/Linux
 I: ls -l /bin
   lrwxrwxrwx 1 root root 7 Nov 22 14:40 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/25459/tmp/hooks/D02_print_environment finished
+I: user script /srv/workspace/pbuilder/19578/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -154,7 +186,7 @@
 Get: 36 http://deb.debian.org/debian unstable/main armhf golang-github-muesli-mango-dev all 0.2.0-2 [4772 B]
 Get: 37 http://deb.debian.org/debian unstable/main armhf golang-github-muesli-roff-dev all 0.1.0-2 [3964 B]
 Get: 38 http://deb.debian.org/debian unstable/main armhf golang-github-spf13-pflag-dev all 1.0.6~git20210604-d5e0c0615ace-1 [43.0 kB]
-Fetched 62.0 MB in 1s (60.7 MB/s)
+Fetched 62.0 MB in 4s (16.7 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%
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(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 ... 19680 files and directories currently installed.)
@@ -321,7 +353,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/golang-github-muesli-mango-pflag-0.1.0/ && 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-muesli-mango-pflag_0.1.0-1_source.changes
+I: user script /srv/workspace/pbuilder/19578/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for unstable
+I: user script /srv/workspace/pbuilder/19578/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/golang-github-muesli-mango-pflag-0.1.0/ && 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-muesli-mango-pflag_0.1.0-1_source.changes
 dpkg-buildpackage: info: source package golang-github-muesli-mango-pflag
 dpkg-buildpackage: info: source version 0.1.0-1
 dpkg-buildpackage: info: source distribution unstable
@@ -339,16 +375,16 @@
    dh_autoreconf -O--builddirectory=debian/build -O--buildsystem=golang
    dh_auto_configure -O--builddirectory=debian/build -O--buildsystem=golang
    dh_auto_build -O--builddirectory=debian/build -O--buildsystem=golang
-	cd debian/build && go install -trimpath -v -p 3 github.com/muesli/mango-pflag
-internal/unsafeheader
+	cd debian/build && go install -trimpath -v -p 4 github.com/muesli/mango-pflag
 internal/goarch
-internal/cpu
 internal/byteorder
+internal/cpu
+internal/unsafeheader
 internal/abi
-internal/chacha8rand
-internal/bytealg
 internal/coverage/rtcov
+internal/chacha8rand
 internal/godebugs
+internal/bytealg
 internal/goexperiment
 internal/goos
 internal/profilerecord
@@ -357,28 +393,29 @@
 internal/stringslite
 runtime/internal/math
 runtime/internal/sys
-internal/runtime/exithook
 cmp
 internal/itoa
 internal/race
 math/bits
 unicode/utf8
+internal/runtime/exithook
 sync/atomic
-math
-runtime
 unicode
+math
 internal/asan
 internal/msan
 encoding
 internal/nettrace
+runtime
 sync
-iter
 internal/reflectlite
-slices
+iter
 internal/weak
-internal/testlog
+slices
 internal/bisect
+internal/testlog
 internal/singleflight
+runtime/cgo
 errors
 sort
 strconv
@@ -387,8 +424,8 @@
 path
 internal/godebug
 syscall
-strings
 reflect
+strings
 bytes
 bufio
 vendor/golang.org/x/net/dns/dnsmessage
@@ -397,27 +434,26 @@
 internal/syscall/execenv
 math/rand/v2
 internal/concurrent
-encoding/binary
-internal/fmtsort
 unique
+internal/fmtsort
+encoding/binary
+net/netip
 io/fs
 internal/poll
-encoding/base64
 internal/filepathlite
+encoding/base64
 context
-net/netip
-runtime/cgo
 os
 fmt
+net
 github.com/muesli/mango
 encoding/csv
 encoding/hex
 flag
-net
 github.com/spf13/pflag
 github.com/muesli/mango-pflag
    dh_auto_test -O--builddirectory=debian/build -O--buildsystem=golang
-	cd debian/build && go test -vet=off -v -p 3 github.com/muesli/mango-pflag
+	cd debian/build && go test -vet=off -v -p 4 github.com/muesli/mango-pflag
 ?   	github.com/muesli/mango-pflag	[no test files]
    create-stamp debian/debhelper-build-stamp
    dh_testroot -O--builddirectory=debian/build -O--buildsystem=golang
@@ -445,12 +481,14 @@
 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/19578/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/19578/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/25459 and its subdirectories
-I: Current time: Tue Dec 17 19:30:40 -12 2024
-I: pbuilder-time-stamp: 1734507040
+I: removing directory /srv/workspace/pbuilder/19578 and its subdirectories
+I: Current time: Wed Dec 18 21:33:41 +14 2024
+I: pbuilder-time-stamp: 1734507221