Diff of the two buildlogs:

--
--- b1/build.log	2020-05-21 09:01:08.144811278 +0000
+++ b2/build.log	2020-05-21 09:07:09.517874937 +0000
@@ -1,6 +1,6 @@
 I: pbuilder: network access will be disabled during build
-I: Current time: Wed May 20 20:59:12 -12 2020
-I: pbuilder-time-stamp: 1590051552
+I: Current time: Thu May 21 23:01:19 +14 2020
+I: pbuilder-time-stamp: 1590051679
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/buster-reproducible-base.tgz]
 I: copying local configuration
@@ -17,7 +17,7 @@
 I: Extracting source
 gpgv: unknown type of key resource 'trustedkeys.kbx'
 gpgv: keyblock resource '/root/.gnupg/trustedkeys.kbx': General error
-gpgv: Signature made Wed Aug 23 02:23:54 2017 -12
+gpgv: Signature made Thu Aug 24 04:23:54 2017 +14
 gpgv:                using RSA key 2A7974AE2FC152D77867DA4ACE1F9C674512C22A
 gpgv: Can't check signature: No public key
 dpkg-source: warning: failed to verify signature on ./ruby-concurrent-ext_1.0.5-1.dsc
@@ -26,6 +26,170 @@
 dpkg-source: info: unpacking ruby-concurrent-ext_1.0.5-1.debian.tar.xz
 I: using fakeroot in build.
 I: Installing the build-deps
+I: user script /srv/workspace/pbuilder/7309/tmp/hooks/D01_modify_environment starting
+debug: Running on jtk1b.
+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
+Removing 'diversion of /bin/sh to /bin/sh.distrib by dash'
+Adding 'diversion of /bin/sh to /bin/sh.distrib by bash'
+Removing 'diversion of /usr/share/man/man1/sh.1.gz to /usr/share/man/man1/sh.distrib.1.gz by dash'
+Adding 'diversion of /usr/share/man/man1/sh.1.gz to /usr/share/man/man1/sh.distrib.1.gz by 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/7309/tmp/hooks/D01_modify_environment finished
+I: user script /srv/workspace/pbuilder/7309/tmp/hooks/D02_print_environment starting
+I: set
+  BASH=/bin/sh
+  BASHOPTS=checkwinsize:cmdhist:complete_fullquote:extquote:force_fignore:globasciiranges:hostcomplete:interactive_comments:progcomp:promptvars:sourcepath
+  BASH_ALIASES=()
+  BASH_ARGC=()
+  BASH_ARGV=()
+  BASH_CMDS=()
+  BASH_LINENO=([0]="12" [1]="0")
+  BASH_SOURCE=([0]="/tmp/hooks/D02_print_environment" [1]="/tmp/hooks/D02_print_environment")
+  BASH_VERSINFO=([0]="5" [1]="0" [2]="3" [3]="1" [4]="release" [5]="arm-unknown-linux-gnueabihf")
+  BASH_VERSION='5.0.3(1)-release'
+  BUILDDIR=/build
+  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=
+  EUID=0
+  FUNCNAME=([0]="Echo" [1]="main")
+  GROUPS=()
+  HOME=/root
+  HOSTNAME=i-capture-the-hostname
+  HOSTTYPE=arm
+  HOST_ARCH=armhf
+  IFS=' 	
+  '
+  INVOCATION_ID=6e3d36245cb84684aaea23d7299ac0c2
+  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=7309
+  PS4='+ '
+  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/tmp.hW2myQ9ieA/pbuilderrc_9bIv --hookdir /etc/pbuilder/rebuild-hooks --debbuildopts -b --basetgz /var/cache/pbuilder/buster-reproducible-base.tgz --buildresult /srv/reproducible-results/rbuild-debian/tmp.hW2myQ9ieA/b2 --logfile b2/build.log ruby-concurrent-ext_1.0.5-1.dsc'
+  SUDO_GID=114
+  SUDO_UID=110
+  SUDO_USER=jenkins
+  TERM=unknown
+  TZ=/usr/share/zoneinfo/Etc/GMT-14
+  UID=0
+  USER=root
+  _='I: set'
+  http_proxy=http://10.0.0.15:8000/
+I: uname -a
+  Linux i-capture-the-hostname 4.19.0-9-armmp-lpae #1 SMP Debian 4.19.118-2 (2020-04-29) armv7l GNU/Linux
+I: ls -l /bin
+  total 3328
+  -rwxr-xr-x 1 root root 767656 Apr 18  2019 bash
+  -rwxr-xr-x 3 root root  26052 Jul 11  2019 bunzip2
+  -rwxr-xr-x 3 root root  26052 Jul 11  2019 bzcat
+  lrwxrwxrwx 1 root root      6 Jul 11  2019 bzcmp -> bzdiff
+  -rwxr-xr-x 1 root root   2227 Jul 11  2019 bzdiff
+  lrwxrwxrwx 1 root root      6 Jul 11  2019 bzegrep -> bzgrep
+  -rwxr-xr-x 1 root root   4877 Jun 25  2019 bzexe
+  lrwxrwxrwx 1 root root      6 Jul 11  2019 bzfgrep -> bzgrep
+  -rwxr-xr-x 1 root root   3641 Jul 11  2019 bzgrep
+  -rwxr-xr-x 3 root root  26052 Jul 11  2019 bzip2
+  -rwxr-xr-x 1 root root   9636 Jul 11  2019 bzip2recover
+  lrwxrwxrwx 1 root root      6 Jul 11  2019 bzless -> bzmore
+  -rwxr-xr-x 1 root root   1297 Jul 11  2019 bzmore
+  -rwxr-xr-x 1 root root  22432 Mar  1  2019 cat
+  -rwxr-xr-x 1 root root  38868 Mar  1  2019 chgrp
+  -rwxr-xr-x 1 root root  38836 Mar  1  2019 chmod
+  -rwxr-xr-x 1 root root  42972 Mar  1  2019 chown
+  -rwxr-xr-x 1 root root  88376 Mar  1  2019 cp
+  -rwxr-xr-x 1 root root  75516 Jan 18  2019 dash
+  -rwxr-xr-x 1 root root  71648 Mar  1  2019 date
+  -rwxr-xr-x 1 root root  51212 Mar  1  2019 dd
+  -rwxr-xr-x 1 root root  55672 Mar  1  2019 df
+  -rwxr-xr-x 1 root root  88444 Mar  1  2019 dir
+  -rwxr-xr-x 1 root root  54872 Jan 10  2019 dmesg
+  lrwxrwxrwx 1 root root      8 Sep 27  2018 dnsdomainname -> hostname
+  lrwxrwxrwx 1 root root      8 Sep 27  2018 domainname -> hostname
+  -rwxr-xr-x 1 root root  22364 Mar  1  2019 echo
+  -rwxr-xr-x 1 root root     28 Jan  8  2019 egrep
+  -rwxr-xr-x 1 root root  18260 Mar  1  2019 false
+  -rwxr-xr-x 1 root root     28 Jan  8  2019 fgrep
+  -rwxr-xr-x 1 root root  47356 Jan 10  2019 findmnt
+  -rwsr-xr-x 1 root root  21980 Apr 23 09:38 fusermount
+  -rwxr-xr-x 1 root root 124508 Jan  8  2019 grep
+  -rwxr-xr-x 2 root root   2345 Jan  6  2019 gunzip
+  -rwxr-xr-x 1 root root   6375 Jan  6  2019 gzexe
+  -rwxr-xr-x 1 root root  64232 Jan  6  2019 gzip
+  -rwxr-xr-x 1 root root  13784 Sep 27  2018 hostname
+  -rwxr-xr-x 1 root root  43044 Mar  1  2019 ln
+  -rwxr-xr-x 1 root root  34932 Jul 27  2018 login
+  -rwxr-xr-x 1 root root  88444 Mar  1  2019 ls
+  -rwxr-xr-x 1 root root  67036 Jan 10  2019 lsblk
+  -rwxr-xr-x 1 root root  47168 Mar  1  2019 mkdir
+  -rwxr-xr-x 1 root root  43040 Mar  1  2019 mknod
+  -rwxr-xr-x 1 root root  26552 Mar  1  2019 mktemp
+  -rwxr-xr-x 1 root root  26024 Jan 10  2019 more
+  -rwsr-xr-x 1 root root  34268 Jan 10  2019 mount
+  -rwxr-xr-x 1 root root   9688 Jan 10  2019 mountpoint
+  -rwxr-xr-x 1 root root  84284 Mar  1  2019 mv
+  lrwxrwxrwx 1 root root      8 Sep 27  2018 nisdomainname -> hostname
+  lrwxrwxrwx 1 root root     14 Feb 15  2019 pidof -> /sbin/killall5
+  -rwxr-xr-x 1 root root  22416 Mar  1  2019 pwd
+  lrwxrwxrwx 1 root root      4 Apr 18  2019 rbash -> bash
+  -rwxr-xr-x 1 root root  26504 Mar  1  2019 readlink
+  -rwxr-xr-x 1 root root  42968 Mar  1  2019 rm
+  -rwxr-xr-x 1 root root  26496 Mar  1  2019 rmdir
+  -rwxr-xr-x 1 root root  14136 Jan 22  2019 run-parts
+  -rwxr-xr-x 1 root root  76012 Dec 23  2018 sed
+  lrwxrwxrwx 1 root root      4 May 21 23:02 sh -> bash
+  lrwxrwxrwx 1 root root      4 May 19 22:29 sh.distrib -> dash
+  -rwxr-xr-x 1 root root  22384 Mar  1  2019 sleep
+  -rwxr-xr-x 1 root root  51124 Mar  1  2019 stty
+  -rwsr-xr-x 1 root root  42472 Jan 10  2019 su
+  -rwxr-xr-x 1 root root  22392 Mar  1  2019 sync
+  -rwxr-xr-x 1 root root 283324 Apr 24  2019 tar
+  -rwxr-xr-x 1 root root   9808 Jan 22  2019 tempfile
+  -rwxr-xr-x 1 root root  63464 Mar  1  2019 touch
+  -rwxr-xr-x 1 root root  18260 Mar  1  2019 true
+  -rwxr-xr-x 1 root root   9636 Apr 23 09:38 ulockmgr_server
+  -rwsr-xr-x 1 root root  21976 Jan 10  2019 umount
+  -rwxr-xr-x 1 root root  22380 Mar  1  2019 uname
+  -rwxr-xr-x 2 root root   2345 Jan  6  2019 uncompress
+  -rwxr-xr-x 1 root root  88444 Mar  1  2019 vdir
+  -rwxr-xr-x 1 root root  21980 Jan 10  2019 wdctl
+  -rwxr-xr-x 1 root root    946 Jan 22  2019 which
+  lrwxrwxrwx 1 root root      8 Sep 27  2018 ypdomainname -> hostname
+  -rwxr-xr-x 1 root root   1983 Jan  6  2019 zcat
+  -rwxr-xr-x 1 root root   1677 Jan  6  2019 zcmp
+  -rwxr-xr-x 1 root root   5879 Jan  6  2019 zdiff
+  -rwxr-xr-x 1 root root     29 Jan  6  2019 zegrep
+  -rwxr-xr-x 1 root root     29 Jan  6  2019 zfgrep
+  -rwxr-xr-x 1 root root   2080 Jan  6  2019 zforce
+  -rwxr-xr-x 1 root root   7584 Jan  6  2019 zgrep
+  -rwxr-xr-x 1 root root   2205 Jan  6  2019 zless
+  -rwxr-xr-x 1 root root   1841 Jan  6  2019 zmore
+  -rwxr-xr-x 1 root root   4552 Jan  6  2019 znew
+I: user script /srv/workspace/pbuilder/7309/tmp/hooks/D02_print_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -194,7 +358,7 @@
 Get: 127 http://deb.debian.org/debian buster/main armhf ruby-setup all 3.4.1-9 [34.2 kB]
 Get: 128 http://deb.debian.org/debian buster/main armhf gem2deb armhf 0.43 [59.2 kB]
 Get: 129 http://deb.debian.org/debian buster/main armhf ruby-concurrent all 1.0.5-3 [159 kB]
-Fetched 40.6 MB in 6s (6527 kB/s)
+Fetched 40.6 MB in 7s (5649 kB/s)
 debconf: delaying package configuration, since apt-utils is not installed
 Selecting previously unselected package libbsd0:armhf.
 (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 ... 18932 files and directories currently installed.)
@@ -742,7 +906,7 @@
 fakeroot is already the newest version (1.23-1).
 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
 I: Building the package
-I: Running cd /build/ruby-concurrent-ext-1.0.5/ && env PATH="/usr/sbin:/usr/bin:/sbin:/bin:/usr/games" HOME="/nonexistent/first-build" dpkg-buildpackage -us -uc -b
+I: Running cd /build/ruby-concurrent-ext-1.0.5/ && env PATH="/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/i/capture/the/path" HOME="/nonexistent/second-build" dpkg-buildpackage -us -uc -b
 dpkg-buildpackage: info: source package ruby-concurrent-ext
 dpkg-buildpackage: info: source version 1.0.5-1
 dpkg-buildpackage: info: source distribution unstable
@@ -772,13 +936,13 @@
    dh_auto_install -O--buildsystem=ruby
 	dh_ruby --install /build/ruby-concurrent-ext-1.0.5/debian/ruby-concurrent-ext
    dh_ruby --install
-/usr/bin/ruby2.5 -S gem build --config-file /dev/null --verbose /tmp/d20200520-30942-10kvkop/gemspec
+/usr/bin/ruby2.5 -S gem build --config-file /dev/null --verbose /tmp/d20200521-13700-us6633/gemspec
 Failed to load /dev/null because it doesn't contain valid YAML hash
   Successfully built RubyGem
   Name: concurrent-ruby-ext
   Version: 1.0.5
   File: concurrent-ruby-ext-1.0.5.gem
-/usr/bin/ruby2.5 -S gem install --config-file /dev/null --verbose --local --verbose --no-rdoc --no-ri --ignore-dependencies --install-dir debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0 /tmp/d20200520-30942-10kvkop/concurrent-ruby-ext-1.0.5.gem
+/usr/bin/ruby2.5 -S gem install --config-file /dev/null --verbose --local --verbose --no-rdoc --no-ri --ignore-dependencies --install-dir debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0 /tmp/d20200521-13700-us6633/concurrent-ruby-ext-1.0.5.gem
 Failed to load /dev/null because it doesn't contain valid YAML hash
 /build/ruby-concurrent-ext-1.0.5/debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/gems/concurrent-ruby-ext-1.0.5/ext/concurrent/atomic_boolean.c
 /build/ruby-concurrent-ext-1.0.5/debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/gems/concurrent-ruby-ext-1.0.5/ext/concurrent/atomic_boolean.h
@@ -794,7 +958,7 @@
 /build/ruby-concurrent-ext-1.0.5/debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/gems/concurrent-ruby-ext-1.0.5/lib/concurrent/atomic_reference/numeric_cas_wrapper.rb
 Building native extensions. This could take a while...
 current directory: /build/ruby-concurrent-ext-1.0.5/debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/gems/concurrent-ruby-ext-1.0.5/ext/concurrent
-/usr/bin/ruby2.5 -r ./siteconf20200520-30951-1rjbm87.rb extconf.rb
+/usr/bin/ruby2.5 -r ./siteconf20200521-13711-e3hdlv.rb extconf.rb
 checking for libkern/OSAtomic.h... no
 creating Makefile
 current directory: /build/ruby-concurrent-ext-1.0.5/debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/gems/concurrent-ruby-ext-1.0.5/ext/concurrent
@@ -843,9 +1007,9 @@
 current directory: /build/ruby-concurrent-ext-1.0.5/debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/gems/concurrent-ruby-ext-1.0.5/ext/concurrent
 make V=1 "DESTDIR=" install
 make[1]: Entering directory '/build/ruby-concurrent-ext-1.0.5/debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/gems/concurrent-ruby-ext-1.0.5/ext/concurrent'
-/bin/mkdir -p . ./.gem.20200520-30951-ryeay7/concurrent
+/bin/mkdir -p . ./.gem.20200521-13711-1afny3k/concurrent
 exit > .sitearchdir.-.concurrent.time
-/usr/bin/install -c -m 0755 extension.so ./.gem.20200520-30951-ryeay7/concurrent
+/usr/bin/install -c -m 0755 extension.so ./.gem.20200521-13711-1afny3k/concurrent
 make[1]: Leaving directory '/build/ruby-concurrent-ext-1.0.5/debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/gems/concurrent-ruby-ext-1.0.5/ext/concurrent'
 
 Successfully installed concurrent-ruby-ext-1.0.5
@@ -893,10 +1057,10 @@
    dh_makeshlibs -O--buildsystem=ruby
    dh_shlibdeps -O--buildsystem=ruby
 dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/extensions/arm-linux/2.5.0/concurrent-ruby-ext-1.0.5/concurrent/extension.so was not linked against libdl.so.2 (it uses none of the library's symbols)
+dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/extensions/arm-linux/2.5.0/concurrent-ruby-ext-1.0.5/concurrent/extension.so was not linked against libgmp.so.10 (it uses none of the library's symbols)
 dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/extensions/arm-linux/2.5.0/concurrent-ruby-ext-1.0.5/concurrent/extension.so was not linked against libm.so.6 (it uses none of the library's symbols)
 dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/extensions/arm-linux/2.5.0/concurrent-ruby-ext-1.0.5/concurrent/extension.so was not linked against libcrypt.so.1 (it uses none of the library's symbols)
 dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/extensions/arm-linux/2.5.0/concurrent-ruby-ext-1.0.5/concurrent/extension.so was not linked against libpthread.so.0 (it uses none of the library's symbols)
-dpkg-shlibdeps: warning: package could avoid a useless dependency if debian/ruby-concurrent-ext/usr/lib/arm-linux-gnueabihf/rubygems-integration/2.5.0/extensions/arm-linux/2.5.0/concurrent-ruby-ext-1.0.5/concurrent/extension.so was not linked against libgmp.so.10 (it uses none of the library's symbols)
    dh_ruby_fixdepends -O--buildsystem=ruby
    dh_installdeb -O--buildsystem=ruby
    dh_gencontrol -O--buildsystem=ruby
@@ -910,12 +1074,14 @@
  dpkg-source --after-build .
 dpkg-buildpackage: info: binary-only upload (no source included)
 I: copying local configuration
+I: user script /srv/workspace/pbuilder/7309/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/7309/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/26517 and its subdirectories
-I: Current time: Wed May 20 21:01:04 -12 2020
-I: pbuilder-time-stamp: 1590051664
+I: removing directory /srv/workspace/pbuilder/7309 and its subdirectories
+I: Current time: Thu May 21 23:07:04 +14 2020
+I: pbuilder-time-stamp: 1590052024