Diff of the two buildlogs:

--
--- b1/build.log	2020-05-06 01:26:33.194448217 +0000
+++ b2/build.log	2020-05-06 01:29:48.254636788 +0000
@@ -1,6 +1,9 @@
-I: pbuilder: network access will be disabled during build
-I: Current time: Mon Jun  7 19:49:21 -12 2021
-I: pbuilder-time-stamp: 1623138561
+W: cgroups are not available on the host, not using them.
+unshare: unshare failed: Cannot allocate memory
+W: pbuilder: unshare CLONE_NEWNET not available
+I: pbuilder: network access is available during build!
+I: Current time: Wed May  6 15:26:36 +14 2020
+I: pbuilder-time-stamp: 1588728396
 I: Building the build Environment
 I: extracting base tarball [/var/cache/pbuilder/buster-reproducible-base.tgz]
 I: copying local configuration
@@ -18,7 +21,7 @@
 I: Extracting source
 gpgv: unknown type of key resource 'trustedkeys.kbx'
 gpgv: keyblock resource '/root/.gnupg/trustedkeys.kbx': General error
-gpgv: Signature made Fri Aug 18 04:24:32 2017 -12
+gpgv: Signature made Sat Aug 19 06:24:32 2017 +14
 gpgv:                using RSA key C2FE4BD271C139B86C533E461E953E27D4311E58
 gpgv: Can't check signature: No public key
 dpkg-source: warning: failed to verify signature on ./cgilib_0.6-1.1.dsc
@@ -27,6 +30,18 @@
 dpkg-source: info: applying cgilib_0.6-1.1.diff.gz
 I: using fakeroot in build.
 I: Installing the build-deps
+I: user script /srv/workspace/pbuilder/10538/tmp/hooks/D01_modify_environment starting
+debug: Running on profitbricks-build12-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
+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/10538/tmp/hooks/D01_modify_environment finished
  -> Attempting to satisfy build-dependencies
  -> Creating pbuilder-satisfydepends-dummy package
 Package: pbuilder-satisfydepends-dummy
@@ -68,7 +83,7 @@
 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/cgilib-0.6/ && env PATH="/usr/sbin:/usr/bin:/sbin:/bin:/usr/games" HOME="/nonexistent/first-build" dpkg-buildpackage -us -uc -b
+I: Running cd /build/cgilib-0.6/ && 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 cgilib
 dpkg-buildpackage: info: source version 0.6-1.1
 dpkg-buildpackage: info: source distribution unstable
@@ -142,13 +157,14 @@
 dpkg-genchanges: info: binary-only upload (no source code included)
  dpkg-source --after-build .
 dpkg-buildpackage: info: binary-only upload (no source included)
-I: copying local configuration
+I: user script /srv/workspace/pbuilder/10538/tmp/hooks/B01_cleanup starting
+I: user script /srv/workspace/pbuilder/10538/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/839 and its subdirectories
-I: Current time: Mon Jun  7 19:49:31 -12 2021
-I: pbuilder-time-stamp: 1623138571
+I: removing directory /srv/workspace/pbuilder/10538 and its subdirectories
+I: Current time: Wed May  6 15:29:47 +14 2020
+I: pbuilder-time-stamp: 1588728587