Right now, the postinst messages are repeated by Portage near end of build process. However, they are followed by some more output, in particular preserved library listing that can get very long. Example (of not so-long listing): --- >>> dev-util/catfish-4.16.0 merged. >>> Regenerating /etc/ld.so.cache... * Messages for package dev-python/python-distutils-extra-2.45: * Log file: /var/log/portage/dev-python:python-distutils-extra-2.45:20210108-123425.log * DISTUTILS_USE_SETUPTOOLS value is probably incorrect * have: DISTUTILS_USE_SETUPTOOLS=rdepend * expected: DISTUTILS_USE_SETUPTOOLS=bdepend >>> Auto-cleaning packages... >>> No outdated packages were found on your system. * GNU info directory index is up-to-date. !!! existing preserved libs: >>> package: dev-tcltk/blt-2.5.3-r1 * - /usr/lib64/libBLT24.so * used by /usr/lib64/python3.6/lib-dynload/_tkinter.cpython-36m-x86_64-linux-gnu.so (dev-lang/python-3.6.12-r1) >>> package: media-libs/qhull-2020.2-r2 * - /usr/lib64/libqhull.so.7 * - /usr/lib64/libqhull.so.7.2.0 * used by /usr/lib/python3.7/site-packages/matplotlib/_qhull.cpython-37m-x86_64-linux-gnu.so (dev-python/matplotlib-3.3.3-r1) * used by /usr/lib/python3.8/site-packages/matplotlib/_qhull.cpython-38-x86_64-linux-gnu.so (dev-python/matplotlib-3.3.3-r1) * used by /usr/lib/python3.9/site-packages/matplotlib/_qhull.cpython-39-x86_64-linux-gnu.so (dev-python/matplotlib-3.3.3-r1) Use emerge @preserved-rebuild to rebuild packages using these libraries --- Please move them to the very end, so that preserved-libs wouldn't cause them to go off-screen.