Diff of the two buildlogs:

--
--- b1/build.log	2024-04-28 00:50:47.851086701 +0000
+++ b2/build.log	2024-04-28 00:53:55.991060815 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sat Apr 27 12:47:45 -12 2024
-I: pbuilder-time-stamp: 1714265265
+I: Current time: Sun Apr 28 14:50:58 +14 2024
+I: pbuilder-time-stamp: 1714265458
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/trixie-reproducible-base.tgz]
 I: copying local configuration
@@ -25,52 +25,84 @@
 dpkg-source: info: unpacking golang-github-buengese-sgzip_0.0~git20220517.9bca1b6-4.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/4647/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/20817/tmp/hooks/D01_modify_environment starting
+debug: Running on virt64z.
+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 28 00:51 /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/20817/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/20817/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='trixie'
-  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]="21" [3]="1" [4]="release" [5]="arm-unknown-linux-gnueabihf")
+  BASH_VERSION='5.2.21(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=trixie
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=arm
+  HOST_ARCH=armhf
   IFS=' 	
   '
-  INVOCATION_ID='3ada85fd578b43d6b07e454699ae48de'
-  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='4647'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=47f70cbb5335412dab56ea3bf4503481
+  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=20817
   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.q6jbnkU6/pbuilderrc_wGAj --distribution trixie --hookdir /etc/pbuilder/first-build-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/trixie-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.q6jbnkU6/b1 --logfile b1/build.log golang-github-buengese-sgzip_0.0~git20220517.9bca1b6-4.dsc'
-  SUDO_GID='113'
-  SUDO_UID='107'
-  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.q6jbnkU6/pbuilderrc_lBt5 --distribution trixie --hookdir /etc/pbuilder/rebuild-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/trixie-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.q6jbnkU6/b2 --logfile b2/build.log golang-github-buengese-sgzip_0.0~git20220517.9bca1b6-4.dsc'
+  SUDO_GID=110
+  SUDO_UID=103
+  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 virt32c 6.1.0-20-armmp-lpae #1 SMP Debian 6.1.85-1 (2024-04-11) armv7l GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-20-arm64 #1 SMP Debian 6.1.85-1 (2024-04-11) aarch64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Apr 27 11:24 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/4647/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Apr 26 11:23 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/20817/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 trixie/main armhf golang-any armhf 2:1.22~3 [5104 B]
 Get: 37 http://deb.debian.org/debian trixie/main armhf golang-github-cespare-xxhash-dev all 2.1.1-2 [8888 B]
 Get: 38 http://deb.debian.org/debian trixie/main armhf golang-github-klauspost-compress-dev all 1.17.7+ds1-1 [33.0 MB]
-Fetched 91.7 MB in 6s (16.2 MB/s)
+Fetched 91.7 MB in 1s (89.9 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 ... 19469 files and directories currently installed.)
@@ -317,7 +349,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/golang-github-buengese-sgzip-0.0~git20220517.9bca1b6/ && 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-buengese-sgzip_0.0~git20220517.9bca1b6-4_source.changes
+I: user script /srv/workspace/pbuilder/20817/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/20817/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/golang-github-buengese-sgzip-0.0~git20220517.9bca1b6/ && 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-buengese-sgzip_0.0~git20220517.9bca1b6-4_source.changes
 dpkg-buildpackage: info: source package golang-github-buengese-sgzip
 dpkg-buildpackage: info: source version 0.0~git20220517.9bca1b6-4
 dpkg-buildpackage: info: source distribution unstable
@@ -335,16 +371,16 @@
    dh_autoreconf -O--builddirectory=_build -O--buildsystem=golang
    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 3 github.com/buengese/sgzip
+	cd _build && go install -trimpath -v -p 4 github.com/buengese/sgzip
 internal/goarch
 internal/unsafeheader
 internal/cpu
 internal/coverage/rtcov
 internal/abi
 internal/chacha8rand
-internal/bytealg
 internal/godebugs
 internal/goexperiment
+internal/bytealg
 internal/goos
 runtime/internal/atomic
 runtime/internal/math
@@ -356,10 +392,10 @@
 unicode/utf8
 internal/itoa
 math/bits
-runtime
-math
 cmp
 slices
+math
+runtime
 internal/reflectlite
 sync
 internal/testlog
@@ -367,30 +403,30 @@
 sort
 io
 strconv
+internal/oserror
+syscall
 bytes
 strings
-internal/oserror
 reflect
-syscall
-bufio
 internal/safefilepath
 path
+bufio
 hash
 hash/crc32
 internal/syscall/unix
 time
 internal/syscall/execenv
-io/fs
 internal/poll
+io/fs
+os
 internal/fmtsort
 encoding/binary
-os
 fmt
 compress/flate
 github.com/klauspost/compress/flate
 github.com/buengese/sgzip
    dh_auto_test -O--builddirectory=_build -O--buildsystem=golang
-	cd _build && go test -vet=off -v -p 3 github.com/buengese/sgzip
+	cd _build && go test -vet=off -v -p 4 github.com/buengese/sgzip
 === RUN   TestDecompressor
 --- PASS: TestDecompressor (0.04s)
 === RUN   TestSeekUnseekable
@@ -401,11 +437,11 @@
 Name: hello.txt
 Name: shesells.txt
 Name: gettysburg
---- PASS: TestDecompressorWithSeek (0.01s)
+--- PASS: TestDecompressorWithSeek (0.00s)
 === RUN   TestReaderAt
 --- PASS: TestReaderAt (0.00s)
 === RUN   TestDecompressFileWithSeek
---- PASS: TestDecompressFileWithSeek (1.13s)
+--- PASS: TestDecompressFileWithSeek (0.82s)
 === RUN   TestMultiSeek
 --- PASS: TestMultiSeek (0.03s)
 === RUN   TestIssue6550
@@ -424,10 +460,10 @@
 === RUN   TestTruncatedGunzip
 --- PASS: TestTruncatedGunzip (0.01s)
 === RUN   TestTruncatedGunzipBlocks
---- PASS: TestTruncatedGunzipBlocks (0.03s)
+--- PASS: TestTruncatedGunzipBlocks (0.04s)
 === RUN   TestAllocations
-    gzip_norace_test.go:31: Allocated 722 bytes per Write on average
---- PASS: TestAllocations (1.09s)
+    gzip_norace_test.go:31: Allocated 2874 bytes per Write on average
+--- PASS: TestAllocations (0.87s)
 === RUN   TestEmpty
 --- PASS: TestEmpty (0.00s)
 === RUN   TestEmptyBlockData
@@ -437,7 +473,7 @@
 === RUN   TestLatin1
 --- PASS: TestLatin1 (0.00s)
 === RUN   TestLatin1RoundTrip
---- PASS: TestLatin1RoundTrip (0.02s)
+--- PASS: TestLatin1RoundTrip (0.01s)
 === RUN   TestWriterFlush
 --- PASS: TestWriterFlush (0.00s)
 === RUN   TestConcat
@@ -445,65 +481,65 @@
 === RUN   TestWriterReset
 --- PASS: TestWriterReset (0.00s)
 === RUN   TestFile1
---- PASS: TestFile1 (0.02s)
+--- PASS: TestFile1 (0.01s)
 === RUN   TestFile10
 --- PASS: TestFile10 (0.11s)
 === RUN   TestFile50
---- PASS: TestFile50 (0.42s)
+--- PASS: TestFile50 (0.43s)
 === RUN   TestFile200
---- PASS: TestFile200 (1.51s)
+--- PASS: TestFile200 (2.01s)
 === RUN   TestGzip1K
---- PASS: TestGzip1K (0.00s)
+--- PASS: TestGzip1K (0.01s)
 === RUN   TestGzip100K
---- PASS: TestGzip100K (0.02s)
+--- PASS: TestGzip100K (0.06s)
 === RUN   TestGzip1M
---- PASS: TestGzip1M (0.16s)
+--- PASS: TestGzip1M (0.45s)
 === RUN   TestGzip10M
---- PASS: TestGzip10M (1.58s)
+--- PASS: TestGzip10M (3.34s)
 === RUN   TestDeterministicLM2
---- PASS: TestDeterministicLM2 (1.22s)
+--- PASS: TestDeterministicLM2 (2.01s)
 === RUN   TestDeterministicBlockLM2
---- PASS: TestDeterministicBlockLM2 (1.26s)
+--- PASS: TestDeterministicBlockLM2 (2.16s)
 === RUN   TestDeterministicL0
---- PASS: TestDeterministicL0 (1.17s)
+--- PASS: TestDeterministicL0 (2.01s)
 === RUN   TestDeterministicBlockL0
---- PASS: TestDeterministicBlockL0 (1.16s)
+--- PASS: TestDeterministicBlockL0 (1.70s)
 === RUN   TestDeterministicL1
---- PASS: TestDeterministicL1 (1.33s)
+--- PASS: TestDeterministicL1 (1.47s)
 === RUN   TestDeterministicBlockL1
---- PASS: TestDeterministicBlockL1 (1.34s)
+--- PASS: TestDeterministicBlockL1 (1.22s)
 === RUN   TestDeterministicL2
---- PASS: TestDeterministicL2 (1.39s)
+--- PASS: TestDeterministicL2 (1.35s)
 === RUN   TestDeterministicBlockL2
---- PASS: TestDeterministicBlockL2 (1.39s)
+--- PASS: TestDeterministicBlockL2 (1.46s)
 === RUN   TestDeterministicL3
---- PASS: TestDeterministicL3 (1.44s)
+--- PASS: TestDeterministicL3 (1.25s)
 === RUN   TestDeterministicBlockL3
---- PASS: TestDeterministicBlockL3 (1.46s)
+--- PASS: TestDeterministicBlockL3 (1.48s)
 === RUN   TestDeterministicL4
---- PASS: TestDeterministicL4 (1.51s)
+--- PASS: TestDeterministicL4 (1.29s)
 === RUN   TestDeterministicBlockL4
---- PASS: TestDeterministicBlockL4 (1.51s)
+--- PASS: TestDeterministicBlockL4 (1.44s)
 === RUN   TestDeterministicL5
---- PASS: TestDeterministicL5 (1.67s)
+--- PASS: TestDeterministicL5 (1.88s)
 === RUN   TestDeterministicBlockL5
---- PASS: TestDeterministicBlockL5 (1.60s)
+--- PASS: TestDeterministicBlockL5 (1.48s)
 === RUN   TestDeterministicL6
---- PASS: TestDeterministicL6 (1.63s)
+--- PASS: TestDeterministicL6 (1.86s)
 === RUN   TestDeterministicBlockL6
---- PASS: TestDeterministicBlockL6 (1.62s)
+--- PASS: TestDeterministicBlockL6 (1.75s)
 === RUN   TestDeterministicL7
---- PASS: TestDeterministicL7 (2.08s)
+--- PASS: TestDeterministicL7 (1.89s)
 === RUN   TestDeterministicBlockL7
---- PASS: TestDeterministicBlockL7 (2.10s)
+--- PASS: TestDeterministicBlockL7 (2.14s)
 === RUN   TestDeterministicL8
---- PASS: TestDeterministicL8 (2.01s)
+--- PASS: TestDeterministicL8 (1.98s)
 === RUN   TestDeterministicBlockL8
---- PASS: TestDeterministicBlockL8 (2.05s)
+--- PASS: TestDeterministicBlockL8 (1.85s)
 === RUN   TestDeterministicL9
---- PASS: TestDeterministicL9 (4.36s)
+--- PASS: TestDeterministicL9 (3.72s)
 === RUN   TestDeterministicBlockL9
---- PASS: TestDeterministicBlockL9 (4.69s)
+--- PASS: TestDeterministicBlockL9 (3.69s)
 === RUN   TestErrors
 --- PASS: TestErrors (0.01s)
 === RUN   TestWriteError
@@ -517,19 +553,19 @@
 === RUN   TestWriteError/level-7
 === RUN   TestWriteError/level-8
 === RUN   TestWriteError/level-9
---- PASS: TestWriteError (0.50s)
+--- PASS: TestWriteError (0.44s)
     --- PASS: TestWriteError/level-0 (0.01s)
-    --- PASS: TestWriteError/level-1 (0.03s)
+    --- PASS: TestWriteError/level-1 (0.01s)
     --- PASS: TestWriteError/level-2 (0.02s)
     --- PASS: TestWriteError/level-3 (0.01s)
     --- PASS: TestWriteError/level-4 (0.01s)
-    --- PASS: TestWriteError/level-5 (0.02s)
-    --- PASS: TestWriteError/level-6 (0.03s)
-    --- PASS: TestWriteError/level-7 (0.09s)
-    --- PASS: TestWriteError/level-8 (0.12s)
+    --- PASS: TestWriteError/level-5 (0.01s)
+    --- PASS: TestWriteError/level-6 (0.02s)
+    --- PASS: TestWriteError/level-7 (0.10s)
+    --- PASS: TestWriteError/level-8 (0.11s)
     --- PASS: TestWriteError/level-9 (0.13s)
 PASS
-ok  	github.com/buengese/sgzip	46.770s
+ok  	github.com/buengese/sgzip	49.841s
    create-stamp debian/debhelper-build-stamp
    dh_testroot -O--builddirectory=_build -O--buildsystem=golang
    dh_prep -O--builddirectory=_build -O--buildsystem=golang
@@ -557,12 +593,14 @@
 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/20817/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/20817/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/4647 and its subdirectories
-I: Current time: Sat Apr 27 12:50:44 -12 2024
-I: pbuilder-time-stamp: 1714265444
+I: removing directory /srv/workspace/pbuilder/20817 and its subdirectories
+I: Current time: Sun Apr 28 14:53:52 +14 2024
+I: pbuilder-time-stamp: 1714265632