Indexing may fail for some documents, for a number of reasons: a helper program may be missing, the document may be corrupt, we may fail to uncompress a file because no file system space is available, etc.
The Recoll indexer in versions 1.21 and later does not
retry failed files by default, because some indexing failures
can be quite costly (for example failing to uncompress a big
file because of insufficient disk space).
Retrying will only occur if an explicit option
(-k) is set on
the recollindex command line, or if a script
executed when recollindex starts up says
so. The script is defined by a configuration variable
(checkneedretryindexscript), and makes a
rather lame attempt at deciding if a helper command may have been
installed, by checking if any of the
common bin directories have changed.
