Diff of the two buildlogs:

--
--- b1/build.log	2023-04-20 10:38:55.690465865 +0000
+++ b2/build.log	2023-04-20 10:40:42.437727621 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Wed May 22 04:59:53 -12 2024
-I: pbuilder-time-stamp: 1716397193
+I: Current time: Fri Apr 21 00:38:59 +14 2023
+I: pbuilder-time-stamp: 1681987139
 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-klauspost-pgzip_1.2.5.orig.tar.gz]
 I: copying [./golang-github-klauspost-pgzip_1.2.5-2.debian.tar.xz]
 I: Extracting source
-gpgv: Signature made Mon Jan 30 02:47:58 2023 -12
+gpgv: Signature made Tue Jan 31 04:47:58 2023 +14
 gpgv:                using EDDSA key 9185D4F57767AEEE6C55D41E7F44FA25EA5514CB
 gpgv: Can't check signature: No public key
 dpkg-source: warning: cannot verify inline signature for ./golang-github-klauspost-pgzip_1.2.5-2.dsc: no acceptable signature found
@@ -25,52 +25,84 @@
 dpkg-source: info: unpacking golang-github-klauspost-pgzip_1.2.5-2.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/5253/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/10220/tmp/hooks/D01_modify_environment starting
+debug: Running on codethink16-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 Apr 21 00:39 /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/10220/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/10220/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='5253'
-  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=10220
   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.SDXGS8cd/pbuilderrc_eZCC --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.SDXGS8cd/b1 --logfile b1/build.log golang-github-klauspost-pgzip_1.2.5-2.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.SDXGS8cd/pbuilderrc_VITP --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.SDXGS8cd/b2 --logfile b2/build.log --extrapackages usrmerge golang-github-klauspost-pgzip_1.2.5-2.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 codethink11-arm64 4.15.0-209-generic #220-Ubuntu SMP Tue Mar 21 19:52:44 UTC 2023 aarch64 GNU/Linux
+  Linux i-capture-the-hostname 4.15.0-209-generic #220-Ubuntu SMP Tue Mar 21 19:52:44 UTC 2023 aarch64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 May 21 04:47 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/5253/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Apr 21 00:25 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/10220/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -150,7 +182,7 @@
 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 golang-github-cespare-xxhash-dev all 2.1.1-2 [8888 B]
 Get: 38 http://deb.debian.org/debian bookworm/main arm64 golang-github-klauspost-compress-dev all 1.15.12+ds1-3 [30.8 MB]
-Fetched 124 MB in 2s (59.2 MB/s)
+Fetched 124 MB in 2s (60.7 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.)
@@ -316,8 +348,17 @@
 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-klauspost-pgzip-1.2.5/ && 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-klauspost-pgzip_1.2.5-2_source.changes
+I: user script /srv/workspace/pbuilder/10220/tmp/hooks/A99_set_merged_usr starting
+Re-configuring usrmerge...
+I: user script /srv/workspace/pbuilder/10220/tmp/hooks/A99_set_merged_usr finished
+hostname: Temporary failure in name resolution
+I: Running cd /build/golang-github-klauspost-pgzip-1.2.5/ && 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-klauspost-pgzip_1.2.5-2_source.changes
 dpkg-buildpackage: info: source package golang-github-klauspost-pgzip
 dpkg-buildpackage: info: source version 1.2.5-2
 dpkg-buildpackage: info: source distribution unstable
@@ -336,17 +377,17 @@
    dh_auto_configure -O--buildsystem=golang
    dh_auto_build -O--buildsystem=golang
 	cd obj-aarch64-linux-gnu && go install -trimpath -v -p 8 github.com/klauspost/pgzip
+internal/goarch
+internal/unsafeheader
 internal/goexperiment
+internal/cpu
 internal/goos
-internal/unsafeheader
-internal/race
-internal/goarch
 sync/atomic
+unicode
+internal/race
 runtime/internal/syscall
 unicode/utf8
-unicode
 internal/abi
-internal/cpu
 runtime/internal/math
 runtime/internal/sys
 internal/itoa
@@ -360,11 +401,11 @@
 internal/testlog
 errors
 sort
-path
 internal/oserror
-io
 internal/safefilepath
+path
 strconv
+io
 syscall
 bytes
 hash
@@ -372,14 +413,14 @@
 hash/crc32
 reflect
 bufio
-internal/syscall/execenv
 internal/syscall/unix
 time
+internal/syscall/execenv
 io/fs
 internal/poll
-os
 internal/fmtsort
 encoding/binary
+os
 fmt
 compress/flate
 github.com/klauspost/compress/flate
@@ -391,7 +432,7 @@
 === RUN   TestDecompressorReset
 --- PASS: TestDecompressorReset (0.00s)
 === RUN   TestDecompressorResetNoRead
---- PASS: TestDecompressorResetNoRead (0.81s)
+--- PASS: TestDecompressorResetNoRead (0.63s)
 === RUN   TestIssue6550
     gunzip_test.go:443: Copy failed (correctly): flate: corrupt input before offset 3
 --- PASS: TestIssue6550 (0.00s)
@@ -400,14 +441,14 @@
 === RUN   TestMultistreamFalse
 --- PASS: TestMultistreamFalse (0.00s)
 === RUN   TestWriteTo
---- PASS: TestWriteTo (0.04s)
+--- PASS: TestWriteTo (0.05s)
 === RUN   TestTruncatedGunzip
---- PASS: TestTruncatedGunzip (0.02s)
+--- PASS: TestTruncatedGunzip (0.01s)
 === RUN   TestTruncatedGunzipBlocks
---- PASS: TestTruncatedGunzipBlocks (0.05s)
+--- PASS: TestTruncatedGunzipBlocks (0.06s)
 === RUN   TestAllocations
-    gzip_norace_test.go:31: Allocated 1032 bytes per Write on average
---- PASS: TestAllocations (0.69s)
+    gzip_norace_test.go:31: Allocated 1457 bytes per Write on average
+--- PASS: TestAllocations (0.59s)
 === RUN   TestEmpty
 --- PASS: TestEmpty (0.01s)
 === RUN   TestRoundTrip
@@ -423,43 +464,43 @@
 === RUN   TestWriterReset
 --- PASS: TestWriterReset (0.00s)
 === RUN   TestFile1
---- PASS: TestFile1 (0.02s)
+--- PASS: TestFile1 (0.01s)
 === RUN   TestFile10
---- PASS: TestFile10 (0.15s)
+--- PASS: TestFile10 (0.09s)
 === RUN   TestFile50
---- PASS: TestFile50 (0.45s)
+--- PASS: TestFile50 (0.26s)
 === RUN   TestFile200
---- PASS: TestFile200 (1.36s)
+--- PASS: TestFile200 (0.87s)
 === RUN   TestGzip1K
 --- PASS: TestGzip1K (0.00s)
 === RUN   TestGzip100K
---- PASS: TestGzip100K (0.02s)
+--- PASS: TestGzip100K (0.01s)
 === RUN   TestGzip1M
---- PASS: TestGzip1M (0.10s)
+--- PASS: TestGzip1M (0.09s)
 === RUN   TestGzip10M
---- PASS: TestGzip10M (1.14s)
+--- PASS: TestGzip10M (0.98s)
 === RUN   TestDeterministicLM2
---- PASS: TestDeterministicLM2 (0.82s)
+--- PASS: TestDeterministicLM2 (0.66s)
 === RUN   TestDeterministicL0
---- PASS: TestDeterministicL0 (0.74s)
+--- PASS: TestDeterministicL0 (0.62s)
 === RUN   TestDeterministicL1
---- PASS: TestDeterministicL1 (0.94s)
+--- PASS: TestDeterministicL1 (0.78s)
 === RUN   TestDeterministicL2
---- PASS: TestDeterministicL2 (0.91s)
+--- PASS: TestDeterministicL2 (0.82s)
 === RUN   TestDeterministicL3
---- PASS: TestDeterministicL3 (1.09s)
+--- PASS: TestDeterministicL3 (0.86s)
 === RUN   TestDeterministicL4
---- PASS: TestDeterministicL4 (1.04s)
+--- PASS: TestDeterministicL4 (0.86s)
 === RUN   TestDeterministicL5
---- PASS: TestDeterministicL5 (1.40s)
+--- PASS: TestDeterministicL5 (1.12s)
 === RUN   TestDeterministicL6
---- PASS: TestDeterministicL6 (1.23s)
+--- PASS: TestDeterministicL6 (0.96s)
 === RUN   TestDeterministicL7
---- PASS: TestDeterministicL7 (1.99s)
+--- PASS: TestDeterministicL7 (1.60s)
 === RUN   TestDeterministicL8
---- PASS: TestDeterministicL8 (1.77s)
+--- PASS: TestDeterministicL8 (1.62s)
 === RUN   TestDeterministicL9
---- PASS: TestDeterministicL9 (3.92s)
+--- PASS: TestDeterministicL9 (3.17s)
 === RUN   TestErrors
 --- PASS: TestErrors (0.01s)
 === RUN   TestWriteError
@@ -473,19 +514,19 @@
 === RUN   TestWriteError/level-7
 === RUN   TestWriteError/level-8
 === RUN   TestWriteError/level-9
---- PASS: TestWriteError (1.07s)
+--- PASS: TestWriteError (0.94s)
     --- PASS: TestWriteError/level-0 (0.04s)
-    --- PASS: TestWriteError/level-1 (0.02s)
-    --- PASS: TestWriteError/level-2 (0.02s)
-    --- PASS: TestWriteError/level-3 (0.05s)
-    --- PASS: TestWriteError/level-4 (0.03s)
+    --- PASS: TestWriteError/level-1 (0.03s)
+    --- PASS: TestWriteError/level-2 (0.03s)
+    --- PASS: TestWriteError/level-3 (0.02s)
+    --- PASS: TestWriteError/level-4 (0.02s)
     --- PASS: TestWriteError/level-5 (0.03s)
-    --- PASS: TestWriteError/level-6 (0.03s)
-    --- PASS: TestWriteError/level-7 (0.23s)
-    --- PASS: TestWriteError/level-8 (0.29s)
-    --- PASS: TestWriteError/level-9 (0.32s)
+    --- PASS: TestWriteError/level-6 (0.04s)
+    --- PASS: TestWriteError/level-7 (0.26s)
+    --- PASS: TestWriteError/level-8 (0.23s)
+    --- PASS: TestWriteError/level-9 (0.23s)
 PASS
-ok  	github.com/klauspost/pgzip	21.870s
+ok  	github.com/klauspost/pgzip	17.764s
    create-stamp debian/debhelper-build-stamp
    dh_testroot -O--buildsystem=golang
    dh_prep -O--buildsystem=golang
@@ -513,12 +554,14 @@
 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/10220/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/10220/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/5253 and its subdirectories
-I: Current time: Wed May 22 05:01:54 -12 2024
-I: pbuilder-time-stamp: 1716397314
+I: removing directory /srv/workspace/pbuilder/10220 and its subdirectories
+I: Current time: Fri Apr 21 00:40:41 +14 2023
+I: pbuilder-time-stamp: 1681987241