Diff of the two buildlogs:

--
--- b1/build.log	2025-02-17 04:09:05.531838207 +0000
+++ b2/build.log	2025-02-17 04:11:01.262632606 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sun Feb 16 16:08:05 -12 2025
-I: pbuilder-time-stamp: 1739765285
+I: Current time: Mon Mar 23 00:32:13 +14 2026
+I: pbuilder-time-stamp: 1774175533
 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 clean-files.patch
 I: using fakeroot in build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/5279/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/103176/tmp/hooks/D01_modify_environment starting
+debug: Running on ionos6-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 Mar 22 10:32 /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/103176/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/103176/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=11 '
-  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]="37" [3]="1" [4]="release" [5]="i686-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=i386
+  DEBIAN_FRONTEND=noninteractive
+  DEB_BUILD_OPTIONS='buildinfo=+all reproducible=+all parallel=21 '
+  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='2a9154a209dd4edca4f233b1bc000bb0'
-  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='5279'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=65f04a2fedad4069a696f50c02ef847b
+  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=103176
   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.z8nIM8ZK/pbuilderrc_W4zT --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.z8nIM8ZK/b1 --logfile b1/build.log mbuffer_20241007+ds1-1.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://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.z8nIM8ZK/pbuilderrc_H4Ya --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.z8nIM8ZK/b2 --logfile b2/build.log mbuffer_20241007+ds1-1.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://213.165.73.152:3128
 I: uname -a
-  Linux ionos2-i386 6.1.0-31-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.128-1 (2025-02-07) x86_64 GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-31-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.128-1 (2025-02-07) 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/5279/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Nov 22  2024 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/103176/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -161,7 +193,7 @@
 Get: 32 http://deb.debian.org/debian trixie/main i386 libgpg-error0 i386 1.51-3 [87.3 kB]
 Get: 33 http://deb.debian.org/debian trixie/main i386 libgcrypt20 i386 1.11.0-7 [799 kB]
 Get: 34 http://deb.debian.org/debian trixie/main i386 openssl i386 3.4.0-2 [1427 kB]
-Fetched 23.1 MB in 0s (87.9 MB/s)
+Fetched 23.1 MB in 1s (43.6 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 ... 19794 files and directories currently installed.)
@@ -317,7 +349,11 @@
 fakeroot is already the newest version (1.37-1).
 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
 I: Building the package
-I: Running cd /build/reproducible-path/mbuffer-20241007+ds1/ && 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  > ../mbuffer_20241007+ds1-1_source.changes
+I: user script /srv/workspace/pbuilder/103176/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for trixie
+I: user script /srv/workspace/pbuilder/103176/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/mbuffer-20241007+ds1/ && 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  > ../mbuffer_20241007+ds1-1_source.changes
 dpkg-buildpackage: info: source package mbuffer
 dpkg-buildpackage: info: source version 20241007+ds1-1
 dpkg-buildpackage: info: source distribution unstable
@@ -440,7 +476,7 @@
 config.status: creating Makefile
 config.status: creating config.h
    dh_auto_build
-	make -j11
+	make -j21
 make[1]: Entering directory '/build/reproducible-path/mbuffer-20241007+ds1'
 [ -d build ] || mkdir build
 touch build/created.stamp
@@ -469,7 +505,7 @@
 gcc -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/mbuffer-20241007+ds1=. -fstack-protector-strong -Wformat -Werror=format-security -Wno-unused-result -DHAVE_CONFIG_H -DPREFIX=\"/usr\" -I. -I. -Wl,-z,relro -Wl,-z,now -Wl,-z,defs -specs=/usr/share/debhelper/dh_package_notes/debian-package-notes.specs build/log.o build/network.o build/mbuffer.o build/hashing.o build/input.o build/common.o build/settings.o build/globals.o -lm -lpthread  -o mbuffer
 make[1]: Leaving directory '/build/reproducible-path/mbuffer-20241007+ds1'
    dh_auto_test
-	make -j11 check "TESTSUITEFLAGS=-j11 --verbose" VERBOSE=1
+	make -j21 check "TESTSUITEFLAGS=-j21 --verbose" VERBOSE=1
 make[1]: Entering directory '/build/reproducible-path/mbuffer-20241007+ds1'
 bash mkversion.sh
 /usr/bin/tar cf test.tar --ignore-failed-read /bin /usr/bin
@@ -478,8 +514,8 @@
 version.h is up-to-date
 openssl md5 > mbuffer.md5 < mbuffer 
 LD_PRELOAD=./idev.so BSIZE=317 IDEV=mbuffer ./mbuffer -s256 -i mbuffer -f -o mbuffer2
+idev.so: d_open = 0xf7d4f5e0
 ./mbuffer -P90 --md5 -i INSTALL -o /dev/null
-idev.so: d_open = 0xf7d4a5e0
 idev.so: open(/proc/meminfo,0x0,...) = 3 (IDEV='mbuffer')
 idev.so: open(/etc/mbuffer.rc,0x0,...) = -1 (IDEV='mbuffer')
 idev.so: open(/usr/etc/mbuffer.rc,0x0,...) = -1 (IDEV='mbuffer')
@@ -490,21 +526,22 @@
 idev.so: open(/dev/tty,0x2,...) = -1 (IDEV='mbuffer')
 mbuffer: warning: No controlling terminal and no autoloader command specified.
 mbuffer: warning: Block size is not a multiple of native input size (317B).
-summary:  251 kiByte in  0.0sec - average of 19.9 MiB/s
-openssl md5 < test.tar > test.md5
 mbuffer: warning: No controlling terminal and no autoloader command specified.
+summary:  251 kiByte in  0.0sec - average of 6352 kiB/s
+openssl md5 < test.tar > test.md5
+
 MD5 hash: 8bb45d9574a827d338e06f010f00c8c1
-summary:  0.0 kiByte in  0.0sec - average of  0.0 kiB/s
+summary:  0.0 kiByte in  0.6sec - average of  0.0 kiB/s
 ./mbuffer -v 5 -i /etc/hostname
-mbuffer: available memory: 18014398508023896kB / -364522 pages
-mbuffer: Cannot allocate that many blocks (4096 * 4294949070 > 2147483647)
+mbuffer: available memory: 18014398509432988kB / -12249 pages
+mbuffer: Cannot allocate that many blocks (4096 * 4294966684 > 2147483647)
 mbuffer: default Numblocks = 1023, default Blocksize = 2097152, buffer size 2095104kiB
 mbuffer: no config file /etc/mbuffer.rc
 mbuffer: no config file /usr/etc/mbuffer.rc
 mbuffer: no config file /build/reproducible-path/mbuffer-20241007+ds1/debian/.debhelper/generated/_source/home/.mbuffer.rc
 mbuffer: default buffer set to 1023 blocks of 2MiB
 mbuffer: Infile = /etc/hostname
-mbuffer: available: 18014398508023896kiB, buffer: 2095104kiB
+mbuffer: available: 18014398509432988kiB, buffer: 2095104kiB
 mbuffer: 1023 blocks with 2MiB
 mbuffer: allocating 2046MiB as buffer
 mbuffer: creating semaphores...
@@ -522,11 +559,11 @@
 mbuffer: 0 senders, 0 hashers
 mbuffer: timeout init: 0.500000 => 0 : 500000
 mbuffer: outputThread: starting output on <stdout>...
-mbuffer: inputThread: starting with threadid 0x7765cb40...
+mbuffer: inputThread: starting with threadid 0x775fcb40...
 mbuffer: inputThread: last block has 9007147715133452 bytes
 mbuffer: inputThread: exiting...
 mbuffer: outputThread: last block has 12 bytes
-ionos2-i386
+ionos6-i386
 mbuffer: outputThread: syncing <stdout>...
 mbuffer: syncing unsupported on <stdout>: omitted.
 mbuffer: outputThread: finished - exiting...
@@ -557,17 +594,35 @@
 	cp test.tar test3.tar; \
 	cp test.md5 test3.md5; \
 fi
+mbuffer: warning: No controlling terminal and no autoloader command specified.
+SKIPPING the IPv4-only test!
 rm -f output-test4.tar.*
+SKIPPING the IPv6-only test!
 rm -f output-test5.tar.*
-SKIPPING the IPv4-only test!
-cat mbuffer | LD_PRELOAD=./tapetest.so ./mbuffer -s10k -f -o output-test5 -H -A "echo '[test5] Replacing tape'" --tapeaware
 cat mbuffer | LD_PRELOAD=./tapetest.so ./mbuffer -s10k -f -o output-test4 -H -A "echo '[test4] Replacing tape'"
-SKIPPING the IPv6-only test!
+cat mbuffer | LD_PRELOAD=./tapetest.so ./mbuffer -s10k -f -o output-test5 -H -A "echo '[test5] Replacing tape'" --tapeaware
+
+[test4] Replacing tape
+
 [test5] Replacing tape
+
 [test4] Replacing tape
+
+[test4] Replacing tape
+sync
+
 [test5] Replacing tape
+
+[test4] Replacing tape
+sync
+
in @ 99.4 MiB/s, out @ 99.4 MiB/s, 70.0 MiB total, buffer   0% full,  82% done
in @ 99.3 MiB/s, out @  131 MiB/s, 2 x 46.0 MiB total, buffer   1% full,  54% done
in @  356 kiB/s, out @  327 kiB/s,  230 kiB total, buffer   0% full
in @  355 kiB/s, out @  355 kiB/s,  250 kiB total, buffer   0% full
+summary: 85.8 MiByte in  0.9sec - average of 97.9 MiB/s
+
in @ 27.5 MiB/s, out @ 23.6 MiB/s, 2 x 52.0 MiB total, buffer   2% full,  61% done
+[test4] Replacing tape
+sync
+
in @  0.0 kiB/s, out @ 40.0 kiB/s,  250 kiB total, buffer   0% full
in @  0.0 kiB/s, out @  0.0 kiB/s,  250 kiB total, buffer   0% full
 MD5 hash: e0b296c0c7d2a1f7d5a614475b2f5a5b
-summary:  251 kiByte in  0.0sec - average of  9.9 MiB/s
+summary:  251 kiByte in  1.3sec - average of  195 kiB/s
 
 
 
@@ -619,16 +674,12 @@
 [INTERCEPT] write(block 5): OK
 [INTERCEPT] write(block 6): ENOSPC (early)
 [INTERCEPT] write(block 6): OK
-[test4] Replacing tape
 cat output-test5* | openssl md5 > test5.md5
-[test4] Replacing tape
 rm -f output-test5 output-test5.*
-[test4] Replacing tape
 sync
-[test4] Replacing tape
-mbuffer: warning: No controlling terminal and no autoloader command specified.
+
 MD5 hash: e0b296c0c7d2a1f7d5a614475b2f5a5b
-summary:  251 kiByte in  0.1sec - average of 3105 kiB/s
+summary:  251 kiByte in  1.5sec - average of  173 kiB/s
 
 
 
@@ -675,42 +726,37 @@
 cat output-test4* | openssl md5 > test4.md5
 rm -f output-test4 output-test4.*
 sync
-sync
-sync
-
in @ 45.5 MiB/s, out @ 45.5 MiB/s, 32.0 MiB total, buffer   0% full,  37% done
in @ 45.5 MiB/s, out @ 34.1 MiB/s, 2 x 12.0 MiB total, buffer   1% full,  14% done
-summary: 85.8 MiByte in  1.1sec - average of 77.1 MiB/s
-
in @ 47.7 MiB/s, out @ 95.5 MiB/s, 2 x 36.0 MiB total, buffer   1% full,  42% donesync
-
in @ 55.8 MiB/s, out @  175 MiB/s, 2 x 80.0 MiB total, buffer   0% full,  93% done
-MD5 hash: 531070fd5fdc9025101ad8420107920f
-summary: 2x 85.8 MiByte in  1.9sec - average of 91.6 MiB/s
-openssl md5 < test1.tar > test1.md5
-rm -f test1.tar
-sync
-diff test5.md5 mbuffer.md5 > test5
-diff test4.md5 mbuffer.md5 > test4
-diff test2.md5 test.md5
+
in @  0.0 kiB/s, out @ 23.9 MiB/s, 2 x 58.0 MiB total, buffer   1% full,  68% donediff test2.md5 test.md5
 diff test3.md5 test.md5
 diff test0.md5 test.md5
-diff test1.md5 test.md5
-rm test3.md5
+diff test5.md5 mbuffer.md5 > test5
+diff test4.md5 mbuffer.md5 > test4
 rm test2.md5
+rm test3.md5
 touch test0
-touch test1
-openssl md5 < test3.tar > test3.md5 
 openssl md5 < test2.tar > test2.md5 
-rm -f test3.tar
+openssl md5 < test3.tar > test3.md5 
+
+MD5 hash: 09843a9945e2432331a27395cb6cca25
+summary: 2x 85.8 MiByte in  2.1sec - average of 83.7 MiB/s
+openssl md5 < test1.tar > test1.md5
 rm -f test2.tar
 sync
-sync
 diff test2.md5 test.md5
+rm -f test3.tar
+touch test2
+sync
 diff test3.md5 test.md5
 touch test3
-touch test2
+rm -f test1.tar
+sync
+diff test1.md5 test.md5
+touch test1
 make[1]: Leaving directory '/build/reproducible-path/mbuffer-20241007+ds1'
    create-stamp debian/debhelper-build-stamp
    dh_prep
    dh_auto_install --destdir=debian/mbuffer/
-	make -j11 install DESTDIR=/build/reproducible-path/mbuffer-20241007\+ds1/debian/mbuffer AM_UPDATE_INFO_DIR=no
+	make -j21 install DESTDIR=/build/reproducible-path/mbuffer-20241007\+ds1/debian/mbuffer AM_UPDATE_INFO_DIR=no
 make[1]: Entering directory '/build/reproducible-path/mbuffer-20241007+ds1'
 bash mkversion.sh
 /usr/bin/install -c -d -m 755 /build/reproducible-path/mbuffer-20241007+ds1/debian/mbuffer/etc
@@ -757,12 +803,14 @@
 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/103176/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/103176/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/5279 and its subdirectories
-I: Current time: Sun Feb 16 16:09:04 -12 2025
-I: pbuilder-time-stamp: 1739765344
+I: removing directory /srv/workspace/pbuilder/103176 and its subdirectories
+I: Current time: Mon Mar 23 00:33:59 +14 2026
+I: pbuilder-time-stamp: 1774175639