[Xapian-discuss] Flint Database 'Can't acquire write lock'?

[Josef Novak]

Hi,

 I'm using xapian-core-0.9.9, built on a 64bit linux machine
(Linux 2.4.21-143-smp x86_64 unknown ), employing a bash shell.  I
have successfully built several quartz databases of various sizes, and
am trying to construct a flint database now, using the same code.  As
per the readme page
( http://wiki.xapian.org/FlintBackend_2fHowToCreateAFlintDatabase )
I tried:
$ export XAPIAN_PREFER_FLINT=True

however this then resulted in a 'Exception: Unable to acquire database
write lock on test'
message.  If I then
$ unset XAPIAN_PREFER_FLINT

and rerun my program it builds the database without complaint.

I was able to duplicate this sequence of events using the unchanged
simpleindex program that can be found in the examples subdirectory of
xapian-core-0.9.9. I started without specifying the
XAPIAN_PREFER_FLINT environment variable, meaning (I think) that the
resulting database should be built according to the quartz
specification.

First I created a simple test file, containing 3 entries, to index:
--begin doc---
this is a test

this is another test

this is a third and final test
--end doc--

I think ran the following command:
$  cat test.txt | ./simpleindex testdb

and searched the resulting db:
$ ./simplesearch testdb/ test
Performing query `Xapian::Query(test)'
3 results found
ID 1 99% [this is a test]
ID 2 99% [this is another test]
ID 3 86% [this is a third and final test]

Everything worked fine.  I then exported the XAPIAN_PREFER_FLINT variable:
$ export XAPIAN_PREFER_FLINT=True

and attempted to rebuild the database after first deleting it:
$ rm -rf testdb/
$ cat test.txt | ./simpleindex testdb
Exception: Unable to acquire database write lock on testdb

It didn't work, and I don't know why... I thought perhaps it was
because I hadn't explicitly enabled flint during the configuration and
build process (it is enabled by default though), so reran configure
and recompiled with the --enable-backend-flint option set, but it was
all to no avail.  Any suggestions about what might be the root of this
problem  will be greatly appreciated.  Perhaps I am just missing
something really simple.

Thanks,

Joe