Merge prohibited due to updated MVA

I am unable to merge some of my indexes. I use the typical main+delta indexes scenario where I want to merge delta into main. Main indexes are sometimes updated using UpdateAttributes(). I got the following error when trying to merge:

$ sudo -u manticore indexer --rotate --merge tur_main_index tur_delta_index
Manticore 2.8.2 4e81114d@190402 release
Copyright (c) 2001-2016, Andrew Aksyonoff
Copyright (c) 2008-2016, Sphinx Technologies Inc (
Copyright (c) 2017-2019, Manticore Software LTD (

using config file '/etc/sphinxsearch/sphinx.conf'...
merging index 'tur_delta_index' into index 'tur_main_index'...
ERROR: index 'tur_main_index': merge prohibited due to updated MVA.

It looks like this error happens when an mvp file is present and I can see an mvp file for that index /var/manticore/indices/tur_main.mvp. I tried to run “FLUSH ATTRIBUTES;” from the SphinxQL command line, same merge error. I tried to gracefully stop searchd, same merge error. I tried to remove the mvp files, and I got a segfault. Eventually I recreated the main index.

How can I handle this situation without recreating the main index?

in version 2.8 there is no way to merge indexes with updated MVA attributes - there is no code for that.

However that case was fixed in 3.x version you could switch to that to get issue fixed.

Thank you, tomcat. Your answer was very helpful.