Xapian locking errors with custom query parser

[Michal Sojka]

Hi Austin,

when I switched to using your custom query parser I started experiencing
"Unable to get write lock" errors when I run my initial tagging script.
I thought that this was because I run the script while processing the
mail in Emacs, but today I realized that this happens even without Emacs
and that it can be reproduced by a simple command below.

i=0; while notmuch tag +xxx tag:whatever; do i=$((i+1)); echo $i; done

It seems that sometimes the unlocking of the Xapian database happens
somewhat lazily and when the subsequent command starts I get:

A Xapian exception occurred opening database: Unable to get write lock on /home/wsh/mail/.notmuch/xapian: already locked

This happens almost regularly after a few iterations of the loop even if
the query doesn't match anything. 

Do you have an idea what may cause this?

Can you reproduce this on your system?

The version I use can be obtained from

  git://rtime.felk.cvut.cz/notmuch.git custom-query-pasrser

Thanks
-Michal