/usr/share/texmf/tex/latex/beamer/base/themes/theme/compatibility/ is in latex-beamer 3.24-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/texmf/tex/latex/beamer/base/themes/theme/compatibility/beamerthemebars.sty
/usr/share/texmf/tex/latex/beamer/base/themes/theme/compatibility/beamerthemeclassic.sty
/usr/share/texmf/tex/latex/beamer/base/themes/theme/compatibility/beamerthemecompatibility.sty
/usr/share/texmf/tex/latex/beamer/base/themes/theme/compatibility/beamerthemelined.sty
/usr/share/texmf/tex/latex/beamer/base/themes/theme/compatibility/beamerthemeplain.sty
/usr/share/texmf/tex/latex/beamer/base/themes/theme/compatibility/beamerthemeshadow.sty
/usr/share/texmf/tex/latex/beamer/base/themes/theme/compatibility/beamerthemesidebar.sty
/usr/share/texmf/tex/latex/beamer/base/themes/theme/compatibility/beamerthemesplit.sty
/usr/share/texmf/tex/latex/beamer/base/themes/theme/compatibility/beamerthemetree.sty