The root cause is the port is performing strip for non-binary files at post-install target.
strip leaves temporary files named like sbin/ecp.fQXqex4S if it failed to strip. As a result, poudriere complains there's a orphaned file.
Error: Orphaned: sbin/ecp.fQXqex4S
And what is worse, actually binaries are not stripped at all. If even a single file fails to strip, all files are not stripped. In the following example, not only c.plaintext but {a,b,c}.binary are not stripped.
$ strip a.binary b.binary c.plaintext d.binary
I've changed post-install target to perform strip only for executables and shared libraries. Also pet the following poudrier warnings & errors.
Warning: 'sbin/checkgid' is not stripped consider trying INSTALL_TARGET=install-strip or using ${STRIP_CMD} Warning: 'sbin/htcacheclean' is not stripped consider trying INSTALL_TARGET=install-strip or using ${STRIP_CMD} Warning: 'sbin/httpd' is not stripped consider trying INSTALL_TARGET=install-strip or using ${STRIP_CMD} Warning: 'sbin/rotatelogs' is not stripped consider trying INSTALL_TARGET=install-strip or using ${STRIP_CMD} Warning: 'sbin/fcgistarter' is not stripped consider trying INSTALL_TARGET=install-strip or using ${STRIP_CMD} Error: /usr/local/bin/ab is linked to /usr/local/lib/libdb-5.3.so.0 from databases/db5 but it is not declared as a dependency Warning: you need USES+=bdb Error: /usr/local/bin/ab is linked to /usr/local/lib/libgdbm.so.6 from databases/gdbm but it is not declared as a dependency Warning: you need LIB_DEPENDS+=libgdbm.so:databases/gdbm
See also: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=252792