Diff of the two buildlogs:

--
--- b1/build.log	2025-01-20 12:39:53.536628337 +0000
+++ b2/build.log	2025-01-20 12:42:21.893961808 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Mon Jan 20 00:35:00 -12 2025
-I: pbuilder-time-stamp: 1737376500
+I: Current time: Tue Jan 21 02:40:03 +14 2025
+I: pbuilder-time-stamp: 1737376803
 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-emersion-go-pgpmail_0.2.2-1.debian.tar.xz
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/7144/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/3738/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 Jan 20 12:40 /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/3738/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/3738/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]="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=trixie
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=arm
+  HOST_ARCH=armhf
   IFS=' 	
   '
-  INVOCATION_ID='2954abc840fb4eedb5a8b9a41b5a4a8a'
-  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='7144'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=e80e13a7e79745baa2182898dd005a09
+  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=3738
   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.xoTLbRHC/pbuilderrc_Qiom --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.xoTLbRHC/b1 --logfile b1/build.log golang-github-emersion-go-pgpmail_0.2.2-1.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.xoTLbRHC/pbuilderrc_VN9U --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.xoTLbRHC/b2 --logfile b2/build.log golang-github-emersion-go-pgpmail_0.2.2-1.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 virt32a 6.1.0-30-armmp-lpae #1 SMP Debian 6.1.124-1 (2025-01-12) armv7l GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-30-arm64 #1 SMP Debian 6.1.124-1 (2025-01-12) aarch64 GNU/Linux
 I: ls -l /bin
   lrwxrwxrwx 1 root root 7 Nov 22 14:40 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/7144/tmp/hooks/D02_print_environment finished
+I: user script /srv/workspace/pbuilder/3738/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -165,7 +197,7 @@
 Get: 50 http://deb.debian.org/debian trixie/main armhf golang-github-emersion-go-textwrapper-dev all 0.0~git20160606.d0e65e5-2 [3100 B]
 Get: 51 http://deb.debian.org/debian trixie/main armhf golang-github-emersion-go-message-dev all 0.17.0-1 [43.2 kB]
 Get: 52 http://deb.debian.org/debian trixie/main armhf golang-github-protonmail-go-crypto-dev all 1.1.5-1 [335 kB]
-Fetched 82.1 MB in 2s (43.9 MB/s)
+Fetched 82.1 MB in 8s (10.6 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 ... 19569 files and directories currently installed.)
@@ -388,7 +420,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/golang-github-emersion-go-pgpmail-0.2.2/ && 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-emersion-go-pgpmail_0.2.2-1_source.changes
+I: user script /srv/workspace/pbuilder/3738/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/3738/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/golang-github-emersion-go-pgpmail-0.2.2/ && 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-emersion-go-pgpmail_0.2.2-1_source.changes
 dpkg-buildpackage: info: source package golang-github-emersion-go-pgpmail
 dpkg-buildpackage: info: source version 0.2.2-1
 dpkg-buildpackage: info: source distribution unstable
@@ -406,35 +442,35 @@
    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/emersion/go-pgpmail
+	cd _build && go install -trimpath -v -p 4 github.com/emersion/go-pgpmail
+internal/byteorder
 internal/unsafeheader
 internal/goarch
 internal/cpu
+internal/coverage/rtcov
 internal/abi
-internal/byteorder
 internal/chacha8rand
-internal/bytealg
-internal/coverage/rtcov
 internal/godebugs
 internal/goexperiment
 internal/goos
+internal/bytealg
 internal/profilerecord
 internal/runtime/atomic
 internal/runtime/syscall
 internal/stringslite
 runtime/internal/math
-internal/runtime/exithook
 runtime/internal/sys
 internal/race
 sync/atomic
 unicode
+internal/runtime/exithook
 unicode/utf8
 math/bits
-runtime
-math
 cmp
 internal/itoa
+math
 internal/asan
+runtime
 internal/msan
 crypto/internal/alias
 crypto/internal/boring/sig
@@ -444,133 +480,133 @@
 encoding
 image/color
 internal/nettrace
-internal/reflectlite
 iter
+internal/reflectlite
 sync
-slices
 crypto/subtle
+slices
 internal/weak
 internal/bisect
 internal/testlog
 internal/singleflight
-internal/godebug
+runtime/cgo
 errors
-math/rand
+internal/godebug
 io
+sort
+strconv
 bytes
 strings
-runtime/cgo
-bufio
 hash
 internal/oserror
-strconv
 path
 syscall
 crypto
+bufio
 reflect
-time
-internal/syscall/unix
-io/fs
-internal/poll
-internal/fmtsort
-internal/filepathlite
-internal/syscall/execenv
 crypto/cipher
-os
-crypto/internal/randutil
-encoding/binary
 crypto/internal/boring
+crypto/internal/randutil
+math/rand
 crypto/sha256
 crypto/sha512
-encoding/base64
+time
+internal/syscall/unix
+internal/syscall/execenv
 github.com/ProtonMail/go-crypto/openpgp/errors
-sort
 crypto/aes
-github.com/ProtonMail/go-crypto/openpgp/aes/keywrap
 crypto/des
 github.com/ProtonMail/go-crypto/eax
-fmt
 golang.org/x/crypto/cast5
-github.com/ProtonMail/go-crypto/openpgp/armor
 crypto/internal/edwards25519/field
 crypto/internal/nistec/fiat
 crypto/internal/edwards25519
+io/fs
+internal/poll
+internal/filepathlite
 github.com/cloudflare/circl/sign
+compress/bzip2
+internal/fmtsort
+os
+encoding/binary
+hash/adler32
+crypto/sha1
+crypto/hmac
+golang.org/x/crypto/hkdf
+image
+encoding/base64
+github.com/ProtonMail/go-crypto/openpgp/armor
+github.com/ProtonMail/go-crypto/openpgp/aes/keywrap
+github.com/cloudflare/circl/internal/sha3
+golang.org/x/crypto/blake2b
+crypto/internal/nistec
+image/internal/imageutil
+fmt
+image/jpeg
+golang.org/x/crypto/argon2
+golang.org/x/sys/cpu
+io/ioutil
+golang.org/x/crypto/sha3
+crypto/ecdh
+context
+vendor/golang.org/x/net/dns/dnsmessage
+math/rand/v2
+golang.org/x/text/transform
+internal/concurrent
 math/big
 encoding/hex
+compress/flate
 github.com/ProtonMail/go-crypto/ocb
 github.com/ProtonMail/go-crypto/openpgp/internal/algorithm
-github.com/cloudflare/circl/internal/sha3
-compress/bzip2
-compress/flate
-hash/adler32
+github.com/ProtonMail/go-crypto/openpgp/s2k
+unique
 compress/zlib
-crypto/internal/nistec
-crypto/sha1
+mime
+net/netip
 crypto/rand
 crypto/internal/boring/bbig
 crypto/internal/bigmod
-encoding/asn1
-crypto/rsa
-crypto/ecdh
 crypto/elliptic
+encoding/asn1
 github.com/ProtonMail/go-crypto/openpgp/internal/encoding
-vendor/golang.org/x/crypto/cryptobyte
 github.com/cloudflare/circl/internal/conv
+crypto/rsa
 github.com/cloudflare/circl/math/fp25519
 github.com/ProtonMail/go-crypto/bitcurves
 github.com/ProtonMail/go-crypto/brainpool
 github.com/cloudflare/circl/dh/x25519
-crypto/ecdsa
 github.com/cloudflare/circl/math/fp448
 crypto/ed25519
-github.com/cloudflare/circl/dh/x448
+vendor/golang.org/x/crypto/cryptobyte
 github.com/cloudflare/circl/math
-github.com/cloudflare/circl/sign/ed25519
 github.com/cloudflare/circl/math/mlsbset
-crypto/dsa
+github.com/cloudflare/circl/sign/ed25519
+github.com/cloudflare/circl/dh/x448
 github.com/cloudflare/circl/ecc/goldilocks
+crypto/ecdsa
+crypto/dsa
 github.com/ProtonMail/go-crypto/openpgp/elgamal
-golang.org/x/crypto/blake2b
-github.com/ProtonMail/go-crypto/openpgp/ed25519
-crypto/hmac
-golang.org/x/crypto/argon2
-golang.org/x/crypto/hkdf
-github.com/cloudflare/circl/sign/ed448
 github.com/ProtonMail/go-crypto/openpgp/x25519
-github.com/ProtonMail/go-crypto/openpgp/s2k
+github.com/ProtonMail/go-crypto/openpgp/ed25519
 github.com/ProtonMail/go-crypto/openpgp/x448
+github.com/cloudflare/circl/sign/ed448
+net
 github.com/ProtonMail/go-crypto/openpgp/internal/ecc
 github.com/ProtonMail/go-crypto/openpgp/ed448
-image
-golang.org/x/sys/cpu
-golang.org/x/crypto/sha3
 github.com/ProtonMail/go-crypto/openpgp/ecdh
 github.com/ProtonMail/go-crypto/openpgp/ecdsa
 github.com/ProtonMail/go-crypto/openpgp/eddsa
-image/internal/imageutil
-io/ioutil
-context
-image/jpeg
-vendor/golang.org/x/net/dns/dnsmessage
-math/rand/v2
 github.com/ProtonMail/go-crypto/openpgp/packet
-internal/concurrent
-unique
-net/netip
-golang.org/x/text/transform
-mime
-net
 github.com/ProtonMail/go-crypto/openpgp
 net/textproto
 github.com/emersion/go-message/textproto
 github.com/emersion/go-pgpmail
    dh_auto_test -O--builddirectory=_build -O--buildsystem=golang
-	cd _build && go test -vet=off -v -p 3 github.com/emersion/go-pgpmail
+	cd _build && go test -vet=off -v -p 4 github.com/emersion/go-pgpmail
 === RUN   TestReader_encryptedSignedPGPMIME
---- PASS: TestReader_encryptedSignedPGPMIME (0.04s)
+--- PASS: TestReader_encryptedSignedPGPMIME (0.02s)
 === RUN   TestReader_encryptedSignedEncapsulatedPGPMIME
---- PASS: TestReader_encryptedSignedEncapsulatedPGPMIME (0.04s)
+--- PASS: TestReader_encryptedSignedEncapsulatedPGPMIME (0.02s)
 === RUN   TestReader_signedPGPMIME
 --- PASS: TestReader_signedPGPMIME (0.00s)
 === RUN   TestReader_signedPGPMIMEInvalid
@@ -580,11 +616,11 @@
 === RUN   TestReader_plaintext
 --- PASS: TestReader_plaintext (0.00s)
 === RUN   TestEncrypt
---- PASS: TestEncrypt (0.11s)
+--- PASS: TestEncrypt (0.06s)
 === RUN   TestSign
---- PASS: TestSign (0.04s)
+--- PASS: TestSign (0.02s)
 PASS
-ok  	github.com/emersion/go-pgpmail	0.260s
+ok  	github.com/emersion/go-pgpmail	0.136s
    create-stamp debian/debhelper-build-stamp
    dh_testroot -O--builddirectory=_build -O--buildsystem=golang
    dh_prep -O--builddirectory=_build -O--buildsystem=golang
@@ -611,12 +647,14 @@
 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/3738/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/3738/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/7144 and its subdirectories
-I: Current time: Mon Jan 20 00:39:47 -12 2025
-I: pbuilder-time-stamp: 1737376787
+I: removing directory /srv/workspace/pbuilder/3738 and its subdirectories
+I: Current time: Tue Jan 21 02:42:18 +14 2025
+I: pbuilder-time-stamp: 1737376938