Homestyx hydra

R1:24845c70b918

Refine error behavior of `bin/search index`

Summary: Fixes T5991. If //all requested documents// failed to index, consider this a catastrophic failure and exit with an error code.

Test Plan:
- Ran `bin/search index --type TASK`, observed successful exit despite a small number of un-indexable documents.
- Ran `bin/search index PHID-TASK-xxx` for an invalid task, observed exception on exit after complete failure.
- Ran normal indexing through daemons.

Reviewers: chad

Reviewed By: chad

Maniphest…
Repository: R1 hydra
Commit Date: Sep 27 2015