This is the result of a daily build exercise from zero as part of our StarlingX/Developer Guide creation: https://wiki.openstack.org/wiki/StarlingX/Developer_Guide One of the things to debug failures during build-pkgs is to find out the failed packages, a "fail" file is created under each package directory: $ find $MY_WORKSPACE/std/results/ -name fail Now we choose one packages from our failing list e.g. .../shim-signed-12-1.tis.2/fail We want to verify the specific build failure for that package but its build.log shows only the Mock Version: $ cat $MY_WORKSPACE/std/results/aarcemor-starlingx-tis-r5-pike-std/build-info-1.0-3.tis/build.log Mock Version: 1.3.4 build-srpm-parallel was successful, we are in build-rpms-parallel stage. One error is common to all packages: 13:37:39 ERROR: Could not find useradd in chroot, maybe the install failed? And this is reflected also as our exit error when we try to enter the mock shell: $ mock -r $MY_BUILD_CFG --shell ... Installed: ... Dependency Installed: ... ... Complete! Finish: yum install ERROR: Could not find useradd in chroot, maybe the install failed? Then we look for that package, and it is part of shadow-utils $ sudo yum whatprovides \*useradd shadow-utils-4.1.5.1-24.el7.x86_64 $ sudo yum install shadow-utils We look at the content from our mock configuration, the shadow-utils is there: $ echo $MY_BUILD_CFG /localdisk/loadbuild/aarcemor/starlingx/std/configs/aarcemor-starlingx-tis-r5-pike-std/aarcemor-starlingx-tis-r5-pike-std.cfg $ vi $MY_BUILD_CFG config_opts['yum_install_command'] = 'install yum yum-utils shadow-utils distribution-gpg-keys' Looking more into the mock environment, we see no content under /var/lib/mock/. Any help is highly appreciated to debug further.