`--pkglist` can't be used with non-regular files

I ran a command similar to following:

createrepo_c \
  --no-database \
  --unique-md-filenames \
  --retain-old-md-by-age=180d \
  --update \
  --pkglist <(find /rpms -type f -name '*.rpm') \
  --recycle-pkglist \
  /rpms

(Put aside for the moment that I could make createrepo_c traverse the directory to find packages; maybe I have another command that outputs the pkglist.)

It printed pkglist file "/dev/fd/63" doesn't exists and exited. It appears --pkglist requires that its arg be a regular file:

createrepo_c/src/cmd_parser.c

Line 511 in f4854bb

if (!g_file_test(options->pkglist, G_FILE_TEST_IS_REGULAR)) {