Diff of the two buildlogs:

--
--- b1/build.log	2025-03-14 00:16:18.400631480 +0000
+++ b2/build.log	2025-03-14 00:23:30.625266483 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Wed Apr 15 18:32:19 -12 2026
-I: pbuilder-time-stamp: 1776321139
+I: Current time: Fri Mar 14 14:16:20 +14 2025
+I: pbuilder-time-stamp: 1741911380
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/unstable-reproducible-base.tgz]
 I: copying local configuration
@@ -43,51 +43,83 @@
 dpkg-source: info: applying Use-URL-constructors-instead-of-toURL.patch
 I: Not using root during the build.
 I: Installing the build-deps
-I: user script /srv/workspace/pbuilder/3655917/tmp/hooks/D02_print_environment starting
+I: user script /srv/workspace/pbuilder/1148926/tmp/hooks/D01_modify_environment starting
+debug: Running on infom01-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 Mar 14 00:16 /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/1148926/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/1148926/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'
+  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=12 '
-  DISTRIBUTION='unstable'
-  HOME='/root'
-  HOST_ARCH='amd64'
+  DIRSTACK=()
+  DISTRIBUTION=unstable
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=x86_64
+  HOST_ARCH=amd64
   IFS=' 	
   '
-  INVOCATION_ID='e52736b060644ca28b2b78ae17cbeb81'
-  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='3655917'
-  PS1='# '
-  PS2='> '
+  INVOCATION_ID=09b7aa7f8d4c4343bce35e4d8c976ed5
+  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=1148926
   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.N1C1qXcQ/pbuilderrc_5KQ9 --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.N1C1qXcQ/b1 --logfile b1/build.log starjava-topcat_4.10.3-1.dsc'
-  SUDO_GID='109'
-  SUDO_UID='104'
-  SUDO_USER='jenkins'
-  TERM='unknown'
-  TZ='/usr/share/zoneinfo/Etc/GMT+12'
-  USER='root'
-  _='/usr/bin/systemd-run'
+  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.N1C1qXcQ/pbuilderrc_kxys --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.N1C1qXcQ/b2 --logfile b2/build.log starjava-topcat_4.10.3-1.dsc'
+  SUDO_GID=109
+  SUDO_UID=104
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  _='I: set'
 I: uname -a
-  Linux infom02-amd64 6.12.12+bpo-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.12-1~bpo12+1 (2025-02-23) x86_64 GNU/Linux
+  Linux i-capture-the-hostname 6.1.0-31-cloud-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 Mar  4  2025 /bin -> usr/bin
-I: user script /srv/workspace/pbuilder/3655917/tmp/hooks/D02_print_environment finished
+  lrwxrwxrwx 1 root root 7 Mar  4 11:20 /bin -> usr/bin
+I: user script /srv/workspace/pbuilder/1148926/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -501,7 +533,7 @@
 Get: 330 http://deb.debian.org/debian unstable/main amd64 starlink-vo-java all 0.2+2025.03.05-1 [703 kB]
 Get: 331 http://deb.debian.org/debian unstable/main amd64 starlink-ttools-java all 3.5.2-1 [5359 kB]
 Get: 332 http://deb.debian.org/debian unstable/main amd64 stilts-doc all 3.5.2-1 [2548 kB]
-Fetched 357 MB in 4s (81.3 MB/s)
+Fetched 357 MB in 6s (57.8 MB/s)
 Preconfiguring packages ...
 Selecting previously unselected package libsystemd-shared:amd64.
 (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 ... 19784 files and directories currently installed.)
@@ -1602,8 +1634,8 @@
 Setting up tzdata (2025a-2) ...
 
 Current default time zone: 'Etc/UTC'
-Local time is now:      Thu Apr 16 06:36:39 UTC 2026.
-Universal Time is now:  Thu Apr 16 06:36:39 UTC 2026.
+Local time is now:      Fri Mar 14 00:20:57 UTC 2025.
+Universal Time is now:  Fri Mar 14 00:20:57 UTC 2025.
 Run 'dpkg-reconfigure tzdata' if you wish to change it.
 
 Setting up libxcb-present0:amd64 (1.17.0-2+b1) ...
@@ -2081,7 +2113,11 @@
 Building tag database...
  -> Finished parsing the build-deps
 I: Building the package
-I: Running cd /build/reproducible-path/starjava-topcat-4.10.3/ && 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  > ../starjava-topcat_4.10.3-1_source.changes
+I: user script /srv/workspace/pbuilder/1148926/tmp/hooks/A99_set_merged_usr starting
+Not re-configuring usrmerge for unstable
+I: user script /srv/workspace/pbuilder/1148926/tmp/hooks/A99_set_merged_usr finished
+hostname: Name or service not known
+I: Running cd /build/reproducible-path/starjava-topcat-4.10.3/ && 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  > ../starjava-topcat_4.10.3-1_source.changes
 dpkg-buildpackage: info: source package starjava-topcat
 dpkg-buildpackage: info: source version 4.10.3-1
 dpkg-buildpackage: info: source distribution unstable
@@ -2166,10 +2202,10 @@
   [javadoc] Javadoc execution
   [javadoc] Loading source files for package uk.ac.starlink.topcat.func...
   [javadoc] Constructing Javadoc information...
-     [java] Apr 15, 2026 6:38:14 PM uk.ac.starlink.fits.InputFactory createFactory
+     [java] Mar 14, 2025 2:22:43 PM uk.ac.starlink.fits.InputFactory createFactory
      [java] INFO: Will read stream (not random-access): jar:file:/usr/share/java/starlink-ttools.jar!/uk/ac/starlink/ttools/scheme/skysimdata.fits
      [java] Writing in-colfits-basic.xml
-     [java] Apr 15, 2026 6:38:15 PM uk.ac.starlink.table.storage.AdaptiveByteStore getDefaultLimit
+     [java] Mar 14, 2025 2:22:43 PM uk.ac.starlink.table.storage.AdaptiveByteStore getDefaultLimit
      [java] INFO: AdaptiveByteStore default memory limit = 2048M * 0.125 = 256M
      [java] No XML for undocumented handler fits-plus
      [java] No XML for undocumented handler colfits-plus
@@ -2178,12 +2214,12 @@
      [java] Writing in-mrt.xml
      [java] Writing in-ascii.xml
      [java] Writing in-csv.xml
+     [java] No XML for undocumented handler fits-healpix
      [java] Writing in-tst.xml
      [java] Writing in-ipac.xml
      [java] Writing in-wdc.xml
      [java] Writing out-fits.xml
      [java] Writing out-colfits.xml
-     [java] No XML for undocumented handler fits-healpix
      [java] Writing out-votable.xml
      [java] Writing out-text.xml
      [java] Writing out-ascii.xml
@@ -2212,7 +2248,7 @@
       [jar] Building jar: /build/reproducible-path/starjava-topcat-4.10.3/lib/starlink-topcat/starlink-topcat_demo.jar
 
 BUILD SUCCESSFUL
-Total time: 37 seconds
+Total time: 26 seconds
 ant javadocs
 Buildfile: /build/reproducible-path/starjava-topcat-4.10.3/build.xml
 
@@ -2237,7 +2273,7 @@
   [javadoc] 2 warnings
 
 BUILD SUCCESSFUL
-Total time: 8 seconds
+Total time: 5 seconds
 make[1]: Leaving directory '/build/reproducible-path/starjava-topcat-4.10.3'
    debian/rules override_dh_auto_test
 make[1]: Entering directory '/build/reproducible-path/starjava-topcat-4.10.3'
@@ -2279,55 +2315,55 @@
 
 run-tests:
     [junit] Testsuite: uk.ac.starlink.topcat.CodecTest
-    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.772 sec
+    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.512 sec
     [junit] 
     [junit] Testsuite: uk.ac.starlink.topcat.ConverterTest
-    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.012 sec
+    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.008 sec
     [junit] 
     [junit] Testsuite: uk.ac.starlink.topcat.DemoTest
-    [junit] Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.818 sec
+    [junit] Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.523 sec
     [junit] 
     [junit] Testsuite: uk.ac.starlink.topcat.HelpTest
-    [junit] Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.031 sec
+    [junit] Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.019 sec
     [junit] 
     [junit] Testsuite: uk.ac.starlink.topcat.JELTest
-    [junit] Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.058 sec
+    [junit] Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.033 sec
     [junit] 
     [junit] Testsuite: uk.ac.starlink.topcat.MethodDocTest
-    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.001 sec
+    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0 sec
     [junit] 
     [junit] ------------- Standard Output ---------------
     [junit] Headless environment - no GUI test
     [junit] ------------- ---------------- ---------------
     [junit] Testsuite: uk.ac.starlink.topcat.ResourceTest
-    [junit] Tests run: 5, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.356 sec
+    [junit] Tests run: 5, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.22 sec
     [junit] 
     [junit] Testsuite: uk.ac.starlink.topcat.func.FuncTest
-    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.031 sec
+    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.029 sec
     [junit] 
     [junit] Testsuite: uk.ac.starlink.topcat.interop.SampControlTest
-    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.001 sec
+    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0 sec
     [junit] 
     [junit] ------------- Standard Error -----------------
     [junit] headless: no SampControlTest
     [junit] ------------- ---------------- ---------------
     [junit] Testsuite: uk.ac.starlink.topcat.plot.ColumnTest
-    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.004 sec
+    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.003 sec
     [junit] 
     [junit] Testsuite: uk.ac.starlink.topcat.plot.StyleTest
-    [junit] Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.065 sec
+    [junit] Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.042 sec
     [junit] 
     [junit] Testsuite: uk.ac.starlink.topcat.plot2.FigureModeTest
-    [junit] Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.9 sec
+    [junit] Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.539 sec
     [junit] 
     [junit] Testsuite: uk.ac.starlink.topcat.plot2.PlotTypeTest
-    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.19 sec
+    [junit] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.125 sec
     [junit] 
 
 test:
 
 BUILD SUCCESSFUL
-Total time: 5 seconds
+Total time: 3 seconds
 make[1]: Leaving directory '/build/reproducible-path/starjava-topcat-4.10.3'
    create-stamp debian/debhelper-build-stamp
    dh_prep
@@ -2353,10 +2389,10 @@
    dh_gencontrol
    dh_md5sums
    dh_builddeb
-dpkg-deb: building package 'topcat' in '../topcat_4.10.3-1_all.deb'.
 dpkg-deb: building package 'topcat-doc' in '../topcat-doc_4.10.3-1_all.deb'.
-dpkg-deb: building package 'starlink-topcat-java' in '../starlink-topcat-java_4.10.3-1_all.deb'.
+dpkg-deb: building package 'topcat' in '../topcat_4.10.3-1_all.deb'.
 dpkg-deb: building package 'starlink-topcat-java-doc' in '../starlink-topcat-java-doc_4.10.3-1_all.deb'.
+dpkg-deb: building package 'starlink-topcat-java' in '../starlink-topcat-java_4.10.3-1_all.deb'.
  dpkg-genbuildinfo --build=binary -O../starjava-topcat_4.10.3-1_amd64.buildinfo
  dpkg-genchanges --build=binary -O../starjava-topcat_4.10.3-1_amd64.changes
 dpkg-genchanges: info: binary-only upload (no source code included)
@@ -2364,12 +2400,14 @@
 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/1148926/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/1148926/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/3655917 and its subdirectories
-I: Current time: Wed Apr 15 18:39:17 -12 2026
-I: pbuilder-time-stamp: 1776321557
+I: removing directory /srv/workspace/pbuilder/1148926 and its subdirectories
+I: Current time: Fri Mar 14 14:23:29 +14 2025
+I: pbuilder-time-stamp: 1741911809