Diff of the two buildlogs:

--
--- b1/build.log	2025-02-15 13:38:36.321983851 +0000
+++ b2/build.log	2025-02-15 13:40:17.801393754 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Sat Feb 15 01:37:42 -12 2025
-I: pbuilder-time-stamp: 1739626662
+I: Current time: Sat Mar 21 10:02:02 +14 2026
+I: pbuilder-time-stamp: 1774036922
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/unstable-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/24101/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/99675/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 20 20:02 /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/99675/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/99675/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='unstable'
-  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=unstable
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=i686
+  HOST_ARCH=i386
   IFS=' 	
   '
-  INVOCATION_ID='74a5b8c1960740c88fd0b814bdcd569d'
-  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='24101'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=9312d9d40e6a4da7aa76f4069ed0738f
+  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=99675
   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.HxLNAFNL/pbuilderrc_9MCE --distribution unstable --hookdir /etc/pbuilder/first-build-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/unstable-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.HxLNAFNL/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.HxLNAFNL/pbuilderrc_wpzf --distribution unstable --hookdir /etc/pbuilder/rebuild-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/unstable-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/r-b-build.HxLNAFNL/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/24101/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Nov 22  2024 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/99675/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 unstable/main i386 libgpg-error0 i386 1.51-3 [87.3 kB]
 Get: 33 http://deb.debian.org/debian unstable/main i386 libgcrypt20 i386 1.11.0-7 [799 kB]
 Get: 34 http://deb.debian.org/debian unstable/main i386 openssl i386 3.4.1-1 [1432 kB]
-Fetched 23.1 MB in 0s (83.0 MB/s)
+Fetched 23.1 MB in 0s (116 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/99675/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for unstable
+I: user script /srv/workspace/pbuilder/99675/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
@@ -479,7 +515,7 @@
 openssl md5 > mbuffer.md5 < mbuffer 
 LD_PRELOAD=./idev.so BSIZE=317 IDEV=mbuffer ./mbuffer -s256 -i mbuffer -f -o mbuffer2
 ./mbuffer -P90 --md5 -i INSTALL -o /dev/null
-idev.so: d_open = 0xf7d725e0
+idev.so: d_open = 0xf7cae5e0
 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')
@@ -490,23 +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 17.6 MiB/s
+summary:  251 kiByte in  0.0sec - average of 40.0 MiB/s
 mbuffer: warning: No controlling terminal and no autoloader command specified.
 MD5 hash: 8bb45d9574a827d338e06f010f00c8c1
 summary:  0.0 kiByte in  0.0sec - average of  0.0 kiB/s
 openssl md5 < test.tar > test.md5
 ./mbuffer -v 5 -i /etc/hostname
-mbuffer: available memory: 18014398507836860kB / -411281 pages
-mbuffer: Cannot allocate that many blocks (4096 * 4294946732 > 2147483647)
-mbuffer: default Numblocks = 1023, default Blocksize = 2097152, buffer size 2095104kiB
+mbuffer: available memory: 1746000kB / 436500 pages
+mbuffer: default Numblocks = 1364, default Blocksize = 65536, buffer size 87296kiB
 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: default buffer set to 1364 blocks of 64kiB
 mbuffer: Infile = /etc/hostname
-mbuffer: available: 18014398507836860kiB, buffer: 2095104kiB
-mbuffer: 1023 blocks with 2MiB
-mbuffer: allocating 2046MiB as buffer
+mbuffer: available: 1746000kiB, buffer: 87296kiB
+mbuffer: 1364 blocks with 64kiB
+mbuffer: allocating 87296kiB as buffer
 mbuffer: creating semaphores...
 mbuffer: opening input /etc/hostname
 mbuffer: enabled O_DIRECT on /etc/hostname
@@ -520,13 +555,13 @@
 mbuffer: checking input device...
 mbuffer: no device on input stream
 mbuffer: 0 senders, 0 hashers
-mbuffer: timeout init: 0.500000 => 0 : 500000
 mbuffer: outputThread: starting output on <stdout>...
-mbuffer: inputThread: starting with threadid 0x77594b40...
-mbuffer: inputThread: last block has 9007147715133452 bytes
+mbuffer: timeout init: 0.500000 => 0 : 500000
+mbuffer: inputThread: starting with threadid 0xf1eadb40...
+mbuffer: inputThread: last block has 281423437103116 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...
@@ -559,18 +594,25 @@
 fi
 rm -f output-test4.tar.*
 rm -f output-test5.tar.*
-SKIPPING the IPv6-only test!
 SKIPPING the IPv4-only test!
+SKIPPING the IPv6-only test!
 cat mbuffer | LD_PRELOAD=./tapetest.so ./mbuffer -s10k -f -o output-test4 -H -A "echo '[test4] Replacing tape'"
 cat mbuffer | LD_PRELOAD=./tapetest.so ./mbuffer -s10k -f -o output-test5 -H -A "echo '[test5] Replacing tape'" --tapeaware
 mbuffer: warning: No controlling terminal and no autoloader command specified.
-[test5] Replacing tape
+
+[test4] Replacing tape
+
 [test4] Replacing tape
+
+[test5] Replacing tape
+
 [test4] Replacing tape
+
 [test5] Replacing tape
+
 [test4] Replacing tape
 MD5 hash: d5f565311c9fb8d2c2bbf9fffb6e3838
-summary:  251 kiByte in  0.0sec - average of 10.5 MiB/s
+summary:  251 kiByte in  0.0sec - average of 13.4 MiB/s
 
 
 
@@ -622,7 +664,7 @@
 [INTERCEPT] write(block 5): OK
 [INTERCEPT] write(block 6): ENOSPC (early)
 [INTERCEPT] write(block 6): OK
-[test4] Replacing tape
+
 [test4] Replacing tape
 cat output-test5* | openssl md5 > test5.md5
 MD5 hash: d5f565311c9fb8d2c2bbf9fffb6e3838
@@ -671,37 +713,37 @@
 [INTERCEPT] write(block 0): OK
 [INTERCEPT] write(block 1): OK
 cat output-test4* | openssl md5 > test4.md5
-rm -f output-test5 output-test5.*
 rm -f output-test4 output-test4.*
+rm -f output-test5 output-test5.*
 sync
 sync
 sync
 sync
-
in @  105 MiB/s, out @  105 MiB/s, 74.0 MiB total, buffer   0% full,  86% done
in @  108 MiB/s, out @ 39.8 MiB/s, 2 x 14.0 MiB total, buffer   3% full,  16% done
-summary: 85.8 MiByte in  0.8sec - average of  105 MiB/s
+
in @ 94.1 MiB/s, out @ 94.1 MiB/s, 66.2 MiB total, buffer   0% full,  77% done
in @ 95.0 MiB/s, out @ 9973 kiB/s, 2 x 3520 kiB total, buffer  75% full,   4% done
+summary: 85.8 MiByte in  0.9sec - average of 92.4 MiB/s
 sync
-
in @ 15.9 MiB/s, out @ 15.9 MiB/s, 2 x 18.0 MiB total, buffer   3% full,  21% donediff test5.md5 mbuffer.md5 > test5
-diff test0.md5 test.md5
-diff test4.md5 mbuffer.md5 > test4
+
in @ 25.3 MiB/s, out @  517 kiB/s, 2 x 3712 kiB total, buffer  96% full,   4% donediff test4.md5 mbuffer.md5 > test4
 diff test2.md5 test.md5
+diff test5.md5 mbuffer.md5 > test5
 diff test3.md5 test.md5
-touch test0
+diff test0.md5 test.md5
 rm test2.md5
 rm test3.md5
+touch test0
 openssl md5 < test2.tar > test2.md5 
 openssl md5 < test3.tar > test3.md5 
 rm -f test3.tar
-
in @  0.0 kiB/s, out @  223 MiB/s, 2 x 74.0 MiB total, buffer   0% full,  86% donesync
 rm -f test2.tar
 sync
-
-MD5 hash: 561ceab7bf39d5ed00d46d0b170f56a8
 diff test3.md5 test.md5
-summary: 2x 85.8 MiByte in  1.8sec - average of 96.3 MiB/s
-openssl md5 < test1.tar > test1.md5
-diff test2.md5 test.md5
 touch test3
+sync
+diff test2.md5 test.md5
 touch test2
+
in @  0.0 kiB/s, out @  271 MiB/s, 2 x 71.7 MiB total, buffer  17% full,  84% done
+MD5 hash: c1c2d07aeaf4e0d01aa041faf11a31d7
+summary: 2x 85.8 MiByte in  2.1sec - average of 83.4 MiB/s
+openssl md5 < test1.tar > test1.md5
 rm -f test1.tar
 sync
 diff test1.md5 test.md5
@@ -710,7 +752,7 @@
    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 +799,14 @@
 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/99675/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/99675/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/24101 and its subdirectories
-I: Current time: Sat Feb 15 01:38:35 -12 2025
-I: pbuilder-time-stamp: 1739626715
+I: removing directory /srv/workspace/pbuilder/99675 and its subdirectories
+I: Current time: Sat Mar 21 10:03:14 +14 2026
+I: pbuilder-time-stamp: 1774036994