Diff of the two buildlogs:

--
--- b1/build.log	2024-04-13 19:19:06.226496199 +0000
+++ b2/build.log	2024-04-13 19:21:42.131866719 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Fri May 16 13:41:03 -12 2025
-I: pbuilder-time-stamp: 1747446063
+I: Current time: Sun Apr 14 09:19:11 +14 2024
+I: pbuilder-time-stamp: 1713035951
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/trixie-reproducible-base.tgz]
 I: copying local configuration
@@ -36,54 +36,86 @@
 dpkg-source: info: applying spelling.patch
 I: using fakeroot in build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/16751/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/53651/tmp/hooks/D01_modify_environment starting
+debug: Running on ionos2-i386.
+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 13 19:19 /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/53651/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/53651/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='i386'
-  DEBIAN_FRONTEND='noninteractive'
-  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=22 '
-  DISTRIBUTION='trixie'
-  HOME='/root'
-  HOST_ARCH='i386'
+  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]="i686-pc-linux-gnu")
+  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=i386
+  DEBIAN_FRONTEND=noninteractive
+  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=10 '
+  DIRSTACK=()
+  DISTRIBUTION=trixie
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=i686
+  HOST_ARCH=i386
   IFS=' 	
   '
-  INVOCATION_ID='61a37c06187c41e0b864f387519f7ecc'
-  LANG='C'
-  LANGUAGE='en_US:en'
-  LC_ALL='C'
-  LD_LIBRARY_PATH='/usr/lib/libeatmydata'
-  LD_PRELOAD='libeatmydata.so'
-  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='16751'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=26ceaf23297b42189fd14da5846a2ba5
+  LANG=C
+  LANGUAGE=de_CH:de
+  LC_ALL=C
+  LD_LIBRARY_PATH=/usr/lib/libeatmydata
+  LD_PRELOAD=libeatmydata.so
+  MACHTYPE=i686-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=53651
   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.NXK56eBK/pbuilderrc_c8ug --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.NXK56eBK/b1 --logfile b1/build.log scheme48_1.9.2-2.dsc'
-  SUDO_GID='112'
-  SUDO_UID='107'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  _='/usr/bin/systemd-run'
-  http_proxy='http://85.184.249.68:3128'
+  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.NXK56eBK/pbuilderrc_Iwad --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.NXK56eBK/b2 --logfile b2/build.log scheme48_1.9.2-2.dsc'
+  SUDO_GID=112
+  SUDO_UID=107
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  _='I: set'
+  http_proxy=http://78.137.99.97:3128
 I: uname -a
-  Linux ionos16-i386 6.1.0-20-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.85-1 (2024-04-11) x86_64 GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-20-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.85-1 (2024-04-11) x86_64 GNU/Linux
 I: ls -l /bin
-  lrwxrwxrwx 1 root root 7 May 15 17:46 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/16751/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Apr 10 11:24 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/53651/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -239,7 +271,7 @@
 Get: 116 http://deb.debian.org/debian trixie/main i386 libtext-glob-perl all 0.11-3 [7676 B]
 Get: 117 http://deb.debian.org/debian trixie/main i386 libfile-find-rule-perl all 0.34-3 [26.6 kB]
 Get: 118 http://deb.debian.org/debian trixie/main i386 dh-elpa all 2.0.17 [31.0 kB]
-Fetched 90.9 MB in 1s (83.1 MB/s)
+Fetched 90.9 MB in 3s (36.1 MB/s)
 debconf: delaying package configuration, since apt-utils is not installed
 Selecting previously unselected package libapparmor1:i386.
 (Reading database ... 
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(Reading database ... 95%
(Reading database ... 100%
(Reading database ... 19874 files and directories currently installed.)
@@ -759,7 +791,11 @@
 fakeroot is already the newest version (1.33-1).
 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
 I: Building the package
-I: Running cd /build/reproducible-path/scheme48-1.9.2/ && 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  > ../scheme48_1.9.2-2_source.changes
+I: user script /srv/workspace/pbuilder/53651/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/53651/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/scheme48-1.9.2/ && 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  > ../scheme48_1.9.2-2_source.changes
 dpkg-buildpackage: info: source package scheme48
 dpkg-buildpackage: info: source version 1.9.2-2
 dpkg-buildpackage: info: source distribution unstable
@@ -906,7 +942,7 @@
    debian/rules override_dh_auto_build
 make[1]: Entering directory '/build/reproducible-path/scheme48-1.9.2'
 dh_auto_build
-	make -j22
+	make -j10
 make[2]: Entering directory '/build/reproducible-path/scheme48-1.9.2'
 i686-linux-gnu-gcc -c -g -O2 -ffile-prefix-map=/build/reproducible-path/scheme48-1.9.2=. -fstack-protector-strong -Wformat -Werror=format-security -pthread -o c/main.o \
 	-DDEFAULT_IMAGE_NAME=\"/usr/lib/scheme48-1.`cat ./build/minor-version-number`/scheme48.image\" \
@@ -972,8 +1008,8 @@
 i686-linux-gnu-gcc -c -Wdate-time -D_FORTIFY_SOURCE=2 -DHAVE_CONFIG_H -I ./c -I./c -I./c/bibop -g -O2 -ffile-prefix-map=/build/reproducible-path/scheme48-1.9.2=. -fstack-protector-strong -Wformat -Werror=format-security -pthread -fPIC -o c/r6rs/r6rs_externals.o c/r6rs/r6rs_externals.c
 i686-linux-gnu-gcc -Wl,-z,relro -Wl,-z,now -pthread -rdynamic -pthread -g -O2 -ffile-prefix-map=/build/reproducible-path/scheme48-1.9.2=. -fstack-protector-strong -Wformat -Werror=format-security -pthread -Wdate-time -D_FORTIFY_SOURCE=2 -o script-interpreter c/script-interpreter.o
 i686-linux-gnu-gcc -o c/r6rs.so c/r6rs/ieee_bytevect.o c/r6rs/r6rs_externals.o  -shared -Wl,-z,relro -Wl,-z,now -pthread -rdynamic -lc 
-i686-linux-gnu-gcc -o c/srfi-27.so  c/srfi-27.o -shared -Wl,-z,relro -Wl,-z,now -pthread -rdynamic -lc
 i686-linux-gnu-gcc -o c/posix.so c/posix/user.o     c/posix/regexp.o c/posix/proc-env.o c/posix/proc.o c/posix/io.o	c/posix/dir.o c/posix/posix.o	c/posix/time.o c/posix/errno.o	c/posix/syslog.o -shared -Wl,-z,relro -Wl,-z,now -pthread -rdynamic -lc
+i686-linux-gnu-gcc -o c/srfi-27.so  c/srfi-27.o -shared -Wl,-z,relro -Wl,-z,now -pthread -rdynamic -lc
 i686-linux-gnu-gcc -o c/ffi-test.so c/ffi-test/ffi-test.o -shared -Wl,-z,relro -Wl,-z,now -pthread -rdynamic -lc
 rm -f c/libscheme48.a;							\
 ar cq c/libscheme48.a c/scheme48vm-32.o c/extension.o c/free.o c/double_to_string.o c/bignum.o c/ffi.o c/external.o c/external-lib.o c/external-init.o c/init.o c/scheme48-bibop-heap-32.o c/bibop/page_alloc.o c/bibop/memory_map.o c/bibop/areas.o c/bibop/generation_gc.o c/bibop/find_all.o c/bibop/check_heap.o c/bibop/utils.o c/bibop/area_roots.o c/bibop/remset.o c/unix/misc.o c/unix/io.o c/unix/fd-io.o c/unix/event.o c/unix/time.o  c/net/socket.o c/net/address.o c/net/net.o c/unix/socket.o c/unix/dynlink.o c/unix/sysexits.o c/fake/glue.o 
@@ -1045,7 +1081,7 @@
    debian/rules override_dh_auto_install
 make[1]: Entering directory '/build/reproducible-path/scheme48-1.9.2'
 dh_auto_install
-	make -j22 install DESTDIR=/build/reproducible-path/scheme48-1.9.2/debian/tmp AM_UPDATE_INFO_DIR=no
+	make -j10 install DESTDIR=/build/reproducible-path/scheme48-1.9.2/debian/tmp AM_UPDATE_INFO_DIR=no
 make[2]: Entering directory '/build/reproducible-path/scheme48-1.9.2'
 for dir in /usr/lib /usr/bin /usr/include /usr/share; do		 \
 	./mkinstalldirs /build/reproducible-path/scheme48-1.9.2/debian/tmp$dir || exit 1;	 \
@@ -1257,9 +1293,9 @@
 dpkg-gencontrol: warning: Built-Using field of package cmuscheme48-el: substitution variable ${misc:Built-Using} used, but is not defined
    dh_md5sums
    dh_builddeb
-dpkg-deb: building package 'scheme48-dbgsym' in '../scheme48-dbgsym_1.9.2-2_i386.deb'.
 dpkg-deb: building package 'scheme48' in '../scheme48_1.9.2-2_i386.deb'.
 dpkg-deb: building package 'scheme48-doc' in '../scheme48-doc_1.9.2-2_all.deb'.
+dpkg-deb: building package 'scheme48-dbgsym' in '../scheme48-dbgsym_1.9.2-2_i386.deb'.
 dpkg-deb: building package 'cmuscheme48-el' in '../cmuscheme48-el_1.9.2-2_all.deb'.
  dpkg-genbuildinfo --build=binary -O../scheme48_1.9.2-2_i386.buildinfo
  dpkg-genchanges --build=binary -O../scheme48_1.9.2-2_i386.changes
@@ -1268,12 +1304,14 @@
 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/53651/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/53651/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/16751 and its subdirectories
-I: Current time: Fri May 16 13:42:05 -12 2025
-I: pbuilder-time-stamp: 1747446125
+I: removing directory /srv/workspace/pbuilder/53651 and its subdirectories
+I: Current time: Sun Apr 14 09:21:41 +14 2024
+I: pbuilder-time-stamp: 1713036101