Diff of the two buildlogs:

--
--- b1/build.log	2025-01-25 03:26:35.901890459 +0000
+++ b2/build.log	2025-01-25 03:28:00.414074189 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Fri Jan 24 15:24:21 -12 2025
-I: pbuilder-time-stamp: 1737775461
+I: Current time: Fri Feb 27 23:49:37 +14 2026
+I: pbuilder-time-stamp: 1772185777
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/trixie-reproducible-base.tgz]
 I: copying local configuration
@@ -22,52 +22,84 @@
 dpkg-source: info: unpacking golang-github-jsternberg-zap-logfmt_1.0.0-1.1.debian.tar.xz
 I: using fakeroot in build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/1393473/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/1026737/tmp/hooks/D01_modify_environment starting
+debug: Running on ionos15-amd64.
+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 Feb 27 09:49 /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/1026737/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/1026737/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='amd64'
-  DEBIAN_FRONTEND='noninteractive'
-  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=20 '
-  DISTRIBUTION='trixie'
-  HOME='/root'
-  HOST_ARCH='amd64'
+  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]="x86_64-pc-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=amd64
+  DEBIAN_FRONTEND=noninteractive
+  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=42 '
+  DIRSTACK=()
+  DISTRIBUTION=trixie
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=x86_64
+  HOST_ARCH=amd64
   IFS=' 	
   '
-  INVOCATION_ID='fc5b3042a7e6493788b68ec71566c62b'
-  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='1393473'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=dcd41f75f0604d83963d64eb72c4a08a
+  LANG=C
+  LANGUAGE=et_EE:et
+  LC_ALL=C
+  MACHTYPE=x86_64-pc-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=1026737
   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.kY1JshM8/pbuilderrc_PfeP --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.kY1JshM8/b1 --logfile b1/build.log golang-github-jsternberg-zap-logfmt_1.0.0-1.1.dsc'
-  SUDO_GID='110'
-  SUDO_UID='105'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  _='/usr/bin/systemd-run'
-  http_proxy='http://46.16.76.132:3128'
+  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.kY1JshM8/pbuilderrc_9uA4 --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.kY1JshM8/b2 --logfile b2/build.log golang-github-jsternberg-zap-logfmt_1.0.0-1.1.dsc'
+  SUDO_GID=111
+  SUDO_UID=106
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  _='I: set'
+  http_proxy=http://213.165.73.152:3128
 I: uname -a
-  Linux ionos1-amd64 6.1.0-30-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.124-1 (2025-01-12) x86_64 GNU/Linux
+  Linux i-capture-the-hostname 6.12.9+bpo-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.9-1~bpo12+1 (2025-01-19) x86_64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 Nov 22 14:40 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/1393473/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Nov 22  2024 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/1026737/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -158,7 +190,7 @@
 Get: 45 http://deb.debian.org/debian trixie/main amd64 golang-go.uber-multierr-dev all 1.6.0-1 [10.6 kB]
 Get: 46 http://deb.debian.org/debian trixie/main amd64 golang-uber-goleak-dev all 1.3.0-1 [18.1 kB]
 Get: 47 http://deb.debian.org/debian trixie/main amd64 golang-go.uber-zap-dev all 1.26.0-1 [124 kB]
-Fetched 66.9 MB in 1s (46.1 MB/s)
+Fetched 66.9 MB in 1s (88.3 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 ... 19856 files and directories currently installed.)
@@ -366,7 +398,11 @@
 fakeroot is already the newest version (1.36.2-1).
 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
 I: Building the package
-I: Running cd /build/reproducible-path/golang-github-jsternberg-zap-logfmt-1.0.0/ && 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-jsternberg-zap-logfmt_1.0.0-1.1_source.changes
+I: user script /srv/workspace/pbuilder/1026737/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/1026737/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/golang-github-jsternberg-zap-logfmt-1.0.0/ && 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-jsternberg-zap-logfmt_1.0.0-1.1_source.changes
 dpkg-buildpackage: info: source package golang-github-jsternberg-zap-logfmt
 dpkg-buildpackage: info: source version 1.0.0-1.1
 dpkg-buildpackage: info: source distribution unstable
@@ -384,158 +420,158 @@
    dh_autoreconf -O--buildsystem=golang
    dh_auto_configure -O--buildsystem=golang
    dh_auto_build -O--buildsystem=golang
-	cd obj-x86_64-linux-gnu && go install -trimpath -v -p 20 github.com/jsternberg/zap-logfmt
-internal/unsafeheader
-internal/byteorder
-internal/coverage/rtcov
-internal/godebugs
-internal/itoa
-math/bits
-internal/msan
-internal/asan
-internal/race
+	cd obj-x86_64-linux-gnu && go install -trimpath -v -p 42 github.com/jsternberg/zap-logfmt
 internal/profilerecord
-cmp
 internal/goos
-internal/runtime/atomic
-encoding
-internal/runtime/syscall
-internal/cpu
+internal/goexperiment
+internal/unsafeheader
+internal/race
 unicode/utf8
-internal/goarch
+math/bits
+unicode/utf16
 sync/atomic
-internal/goexperiment
+internal/nettrace
+vendor/golang.org/x/crypto/internal/alias
 unicode
-unicode/utf16
+encoding
+cmp
+internal/asan
+internal/cpu
 log/internal
+internal/itoa
+internal/msan
 container/list
+internal/godebugs
+crypto/internal/boring/sig
+internal/runtime/atomic
+internal/byteorder
+internal/runtime/syscall
+internal/goarch
 crypto/internal/alias
+internal/coverage/rtcov
 crypto/subtle
-crypto/internal/boring/sig
 vendor/golang.org/x/crypto/cryptobyte/asn1
-internal/nettrace
-vendor/golang.org/x/crypto/internal/alias
 runtime/internal/math
-internal/chacha8rand
 runtime/internal/sys
 internal/abi
+internal/chacha8rand
+internal/runtime/exithook
 internal/bytealg
 math
-internal/runtime/exithook
 internal/stringslite
 runtime
+internal/weak
+iter
 internal/reflectlite
 sync
-iter
-internal/weak
-slices
 maps
-internal/bisect
+slices
 internal/testlog
-go.uber.org/zap/internal/pool
 internal/singleflight
+go.uber.org/zap/internal/pool
+internal/bisect
 runtime/cgo
 errors
+internal/godebug
 sort
-io
 internal/oserror
-strconv
 path
-internal/godebug
+io
+math/rand
 crypto/internal/edwards25519/field
-vendor/golang.org/x/net/dns/dnsmessage
-math/rand/v2
-syscall
+strconv
 crypto/internal/nistec/fiat
 bytes
-strings
+math/rand/v2
+vendor/golang.org/x/net/dns/dnsmessage
+syscall
 hash
 crypto/internal/randutil
-math/rand
+crypto/rc4
+strings
 crypto/internal/edwards25519
-internal/concurrent
-unique
-hash/crc32
-crypto
 reflect
-crypto/rc4
-crypto/md5
-net/netip
-crypto/cipher
+internal/concurrent
 vendor/golang.org/x/text/transform
+crypto/cipher
+crypto
+hash/crc32
 net/http/internal/ascii
 bufio
+unique
+crypto/md5
 crypto/des
 crypto/internal/boring
-crypto/sha512
-crypto/aes
 crypto/hmac
+crypto/sha512
 crypto/sha1
 crypto/sha256
+crypto/aes
 internal/syscall/execenv
 internal/syscall/unix
 time
 vendor/golang.org/x/crypto/hkdf
+net/netip
 go.uber.org/zap/buffer
 context
 io/fs
 internal/poll
 go.uber.org/zap/internal/bufferpool
 go.uber.org/zap/internal/stacktrace
-internal/fmtsort
-encoding/binary
-internal/filepathlite
 embed
+internal/filepathlite
 crypto/internal/nistec
 os
-encoding/base64
-vendor/golang.org/x/crypto/chacha20
-vendor/golang.org/x/crypto/internal/poly1305
-encoding/pem
 crypto/ecdh
+internal/fmtsort
+encoding/binary
 go.uber.org/zap/internal/exit
-fmt
-vendor/golang.org/x/sys/cpu
 path/filepath
-net
+vendor/golang.org/x/sys/cpu
+fmt
+encoding/base64
+vendor/golang.org/x/crypto/chacha20
+vendor/golang.org/x/crypto/internal/poly1305
 vendor/golang.org/x/crypto/sha3
+encoding/pem
 vendor/golang.org/x/crypto/chacha20poly1305
+go.uber.org/zap/internal/color
 log
 flag
-compress/flate
-go.uber.org/zap/internal/color
-net/url
 encoding/hex
-mime/quotedprintable
-net/http/internal
+net/url
 vendor/golang.org/x/net/http2/hpack
+net/http/internal
+compress/flate
+mime/quotedprintable
 encoding/json
 mime
-vendor/golang.org/x/text/unicode/norm
 math/big
+vendor/golang.org/x/text/unicode/norm
 vendor/golang.org/x/text/unicode/bidi
 compress/gzip
 vendor/golang.org/x/text/secure/bidirule
 vendor/golang.org/x/net/idna
 go.uber.org/atomic
-go.uber.org/multierr
-go.uber.org/zap/zapcore
-crypto/rand
-crypto/elliptic
-crypto/internal/bigmod
 crypto/internal/boring/bbig
-crypto/dsa
+crypto/internal/bigmod
 encoding/asn1
+crypto/rand
+crypto/dsa
+crypto/elliptic
+go.uber.org/multierr
 crypto/ed25519
 crypto/internal/hpke
 crypto/internal/mlkem768
+go.uber.org/zap/zapcore
 crypto/rsa
 crypto/x509/pkix
 vendor/golang.org/x/crypto/cryptobyte
-go.uber.org/zap/internal
 crypto/ecdsa
-net/textproto
+go.uber.org/zap/internal
+net
 vendor/golang.org/x/net/http/httpproxy
+net/textproto
 crypto/x509
 vendor/golang.org/x/net/http/httpguts
 mime/multipart
@@ -545,11 +581,11 @@
 go.uber.org/zap
 github.com/jsternberg/zap-logfmt
    dh_auto_test -O--buildsystem=golang
-	cd obj-x86_64-linux-gnu && go test -vet=off -v -p 20 github.com/jsternberg/zap-logfmt
+	cd obj-x86_64-linux-gnu && go test -vet=off -v -p 42 github.com/jsternberg/zap-logfmt
 === RUN   TestEncoderObjectFields
 --- PASS: TestEncoderObjectFields (0.00s)
 PASS
-ok  	github.com/jsternberg/zap-logfmt	0.009s
+ok  	github.com/jsternberg/zap-logfmt	0.004s
    create-stamp debian/debhelper-build-stamp
  fakeroot debian/rules binary
 dh binary --buildsystem=golang --with=golang
@@ -578,12 +614,14 @@
 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/1026737/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/1026737/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/1393473 and its subdirectories
-I: Current time: Fri Jan 24 15:26:35 -12 2025
-I: pbuilder-time-stamp: 1737775595
+I: removing directory /srv/workspace/pbuilder/1026737 and its subdirectories
+I: Current time: Fri Feb 27 23:50:59 +14 2026
+I: pbuilder-time-stamp: 1772185859