Diff of the two buildlogs:

--
--- b1/build.log	2023-04-09 00:37:07.632228791 +0000
+++ b2/build.log	2023-04-09 00:39:10.496148179 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sat Apr  8 12:35:27 -12 2023
-I: pbuilder-time-stamp: 1681000527
+I: Current time: Sat May 11 21:00:11 +14 2024
+I: pbuilder-time-stamp: 1715410811
 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-lunny-log_0.0~git20160921.0.7887c61.orig.tar.xz]
 I: copying [./golang-github-lunny-log_0.0~git20160921.0.7887c61-7.debian.tar.xz]
 I: Extracting source
-gpgv: Signature made Tue May 31 07:44:42 2022 -12
+gpgv: Signature made Wed Jun  1 09:44:42 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-lunny-log_0.0~git20160921.0.7887c61-7.dsc: no acceptable signature found
@@ -25,11 +25,20 @@
 dpkg-source: info: unpacking golang-github-lunny-log_0.0~git20160921.0.7887c61-7.debian.tar.xz
 I: using fakeroot in build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/13671/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/11140/tmp/hooks/D01_modify_environment starting
+debug: Running on codethink15-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
+lrwxrwxrwx 1 root root 4 Jan  6  2023 /bin/sh -> dash
+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/11140/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/11140/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'
+  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'
@@ -39,38 +48,38 @@
   IFS=' 	
   '
   LANG='C'
-  LANGUAGE='en_US:en'
+  LANGUAGE='nl_BE:nl'
   LC_ALL='C'
   MAIL='/var/mail/root'
   OPTIND='1'
-  PATH='/usr/sbin:/usr/bin:/sbin:/bin:/usr/games'
+  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'
-  PPID='13671'
+  PPID='11140'
   PS1='# '
   PS2='> '
   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.eVG6UJfu/pbuilderrc_5Hwu --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.eVG6UJfu/b1 --logfile b1/build.log golang-github-lunny-log_0.0~git20160921.0.7887c61-7.dsc'
+  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.eVG6UJfu/pbuilderrc_ZoD8 --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.eVG6UJfu/b2 --logfile b2/build.log --extrapackages usrmerge golang-github-lunny-log_0.0~git20160921.0.7887c61-7.dsc'
   SUDO_GID='117'
   SUDO_UID='110'
   SUDO_USER='jenkins'
   TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
+  TZ='/usr/share/zoneinfo/Etc/GMT-14'
   USER='root'
   USERNAME='root'
   _='/usr/bin/systemd-run'
   http_proxy='http://192.168.101.16:3128'
 I: uname -a
-  Linux codethink14-arm64 4.15.0-208-generic #220-Ubuntu SMP Mon Mar 20 14:28:12 UTC 2023 aarch64 GNU/Linux
+  Linux i-capture-the-hostname 4.15.0-208-generic #220-Ubuntu SMP Mon Mar 20 14:28:12 UTC 2023 aarch64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Apr  6 22:26 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/13671/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 May 10 06:47 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/11140/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -150,7 +159,7 @@
 Get: 36 http://deb.debian.org/debian bookworm/main arm64 golang-any arm64 2:1.19~1 [5876 B]
 Get: 37 http://deb.debian.org/debian bookworm/main arm64 libsqlite3-dev arm64 3.40.1-2 [979 kB]
 Get: 38 http://deb.debian.org/debian bookworm/main arm64 golang-github-mattn-go-sqlite3-dev arm64 1.14.16~ds1-1 [82.2 kB]
-Fetched 94.4 MB in 2s (37.9 MB/s)
+Fetched 94.4 MB in 5s (17.7 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%
(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 ... 19616 files and directories currently installed.)
@@ -319,10 +328,15 @@
 Reading package lists...
 Building dependency tree...
 Reading state information...
+usrmerge is already the newest version (35).
 fakeroot is already the newest version (1.31-1.2).
 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
 I: Building the package
-I: Running cd /build/golang-github-lunny-log-0.0~git20160921.0.7887c61/ && 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-lunny-log_0.0~git20160921.0.7887c61-7_source.changes
+I: user script /srv/workspace/pbuilder/11140/tmp/hooks/A99_set_merged_usr starting
+Re-configuring usrmerge...
+I: user script /srv/workspace/pbuilder/11140/tmp/hooks/A99_set_merged_usr finished
+hostname: Temporary failure in name resolution
+I: Running cd /build/golang-github-lunny-log-0.0~git20160921.0.7887c61/ && 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-lunny-log_0.0~git20160921.0.7887c61-7_source.changes
 dpkg-buildpackage: info: source package golang-github-lunny-log
 dpkg-buildpackage: info: source version 0.0~git20160921.0.7887c61-7
 dpkg-buildpackage: info: source distribution unstable
@@ -343,18 +357,18 @@
 	cd obj-aarch64-linux-gnu && go install -trimpath -v -p 8 github.com/lunny/log
 internal/goarch
 internal/unsafeheader
-internal/goexperiment
 internal/goos
-internal/race
+internal/goexperiment
 internal/cpu
 runtime/internal/syscall
+internal/race
 sync/atomic
 unicode
-unicode/utf8
-internal/itoa
-internal/abi
 runtime/internal/math
+internal/abi
 runtime/internal/sys
+unicode/utf8
+internal/itoa
 math/bits
 runtime/internal/atomic
 internal/bytealg
@@ -363,20 +377,20 @@
 internal/reflectlite
 sync
 internal/testlog
-sort
 errors
+sort
 internal/oserror
-io
 internal/safefilepath
-strconv
 path
+io
+strconv
 syscall
 bytes
 strings
 reflect
-time
-internal/syscall/unix
 internal/syscall/execenv
+internal/syscall/unix
+time
 context
 internal/poll
 io/fs
@@ -392,9 +406,9 @@
 === RUN   TestFiles
 --- PASS: TestFiles (0.00s)
 === RUN   TestLog
---- PASS: TestLog (0.03s)
+--- PASS: TestLog (0.01s)
 PASS
-ok  	github.com/lunny/log	0.053s
+ok  	github.com/lunny/log	0.034s
    create-stamp debian/debhelper-build-stamp
  fakeroot debian/rules binary
 dh binary --buildsystem=golang --with=golang
@@ -431,12 +445,14 @@
 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/11140/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/11140/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/13671 and its subdirectories
-I: Current time: Sat Apr  8 12:37:06 -12 2023
-I: pbuilder-time-stamp: 1681000626
+I: removing directory /srv/workspace/pbuilder/11140 and its subdirectories
+I: Current time: Sat May 11 21:02:08 +14 2024
+I: pbuilder-time-stamp: 1715410928