GRASS GIS i.histo.match error

Question

I tried to histo-match three red bands of three different landsat8 images, using i.histo.match on Grass7 on Ubuntu and I have this error:

 i.histo.match input=l8_1@list1,l8_2@list1,l8_3@list1 output=mos max=10000
Traceback (most recent call last):
  File "/home/user1/.grass7/addons/scripts/i.histo.match",
line 241, in <module>
    sys.exit(main())
  File "/home/user1/.grass7/addons/scripts/i.histo.match",
line 144, in main
    curs.execute(update_cdf)
sqlite3.OperationalError: database is locked

Do you have any ideas what does it mean? Or what I did incorrectly?

Answer 1

I find out solution, db was obviously busy, so it was essential to stop other processes and finally it had worked.