/usr/share/man/man3/ is in libexecs-dev 1.1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/man/man3/eexecspe.3.gz
/usr/share/man/man3/execse.3.gz
/usr/share/man/man3/execsp.3.gz
/usr/share/man/man3/execspe.3.gz
/usr/share/man/man3/coprocspe.3.gz
/usr/share/man/man3/coprocv.3.gz
/usr/share/man/man3/coprocve.3.gz
/usr/share/man/man3/coprocvp.3.gz
/usr/share/man/man3/coprocvpe.3.gz
/usr/share/man/man3/eexecs.3.gz
/usr/share/man/man3/eexecse.3.gz
/usr/share/man/man3/eexecsp.3.gz
/usr/share/man/man3/coprocess.3.gz
/usr/share/man/man3/esystem.3.gz
/usr/share/man/man3/execs.3.gz
/usr/share/man/man3/popen_nosh.3.gz
/usr/share/man/man3/s2argv.3.gz
/usr/share/man/man3/system_nosh.3.gz
/usr/share/man/man3/coprocs.3.gz
/usr/share/man/man3/coprocse.3.gz
/usr/share/man/man3/coprocsp.3.gz
/usr/share/man/man3/pclose_execs.3.gz
/usr/share/man/man3/pclose_execsp.3.gz
/usr/share/man/man3/pclose_nosh.3.gz
/usr/share/man/man3/popen_execs.3.gz
/usr/share/man/man3/popen_execsp.3.gz
/usr/share/man/man3/system_eexecsp.3.gz
/usr/share/man/man3/system_execs.3.gz
/usr/share/man/man3/system_execsa.3.gz
/usr/share/man/man3/system_execsp.3.gz
/usr/share/man/man3/system_execsr.3.gz
/usr/share/man/man3/system_execsra.3.gz
/usr/share/man/man3/system_execsrp.3.gz