app-backup/bacula-1.38.9 makes use of the 'bacula-no-dir' USE flag, but does not include it in IUSE.
Reassigning to herd, since bug #98505 indicates the maintainer listed in metadata.xml is retired(ish).
Closer examination reveals that ISUE contains bacula-nodir (note the lack of a hyphen between "no" and "dir"). The ebuild itself refers to both forms, so it looks like the hyphened form (bacula-no-dir) is a mistake, and should be switched to bacula-nodir
same for bacula-no-sd and bacula-nosd I fixed it as suggested.