Initializing mlocate database; this may take some time...

[anaymalpani]

While I was trying to install kubuntu-desktop on wsl2(Ubuntu 20.04) on windows 10.

It got stuck at

Initializing mlocate database; this may take some time...

after waiting for a long time(left it for a whole night, as I heard this process takes a lot of time as it parses through every path present on the system)

I closed the process and ran:

sudo dpkg --configure -a

again it's stuck at the same point.

My question is:

How to resolve it?
Why does it take so much time?
Any help will be appreciated.

Thanks in advance!

[onomatopellan]

Probably same problem as #4668. If an application needs to access to a /mnt/ directory in WSL2 then things can become really slow.

[therealkenc]

Right answer. A a practical matter, sudo apt remove mlocate is another way to roll, unless you are actually dead set on using locate(1).

Still wonder, idly, why "forgetting" to update PRUNEPATHS isn't disastrous across the whole Linux ecosystem (obviously, it isn't). I have a crazy slow USB spinny-disk drive with an NTFS filesystem on it, and I have never noticed a Real Linux box try to index it, even though it is ntfs-3g mounted automatically. Shrug. [edit, answering self] Looks like /media is pruned by default on Ubuntu, which is why it never comes up. But not /mnt. Which Ubuntu has never heard of.

Another approach would be to add 9p to PRUNEFS, along side analogous NFS, afs, cifs. [One supposes the maintainers didn't imagine anyone actually using 9p.]

Or.... an alternate-alternate approach would be to change /etc/wsl.conf to use [automount] root=/media. Where God intended it.

[onomatopellan]

@therealkenc if I understand correctly 9p is now a default for PRUNEFS:
https://github.com/sailfishos-mirror/findutils/blob/master/locate/updatedb.sh#L257

edit: In fact it looks like it has been default since 2012

[therealkenc]

Added in 2012, if you can believe it. Why isn't 9p there on my 20.04 after an apt install mlocate? Dunno. But I do take back the "actually using" quip.

[therealkenc]

The pedigree comes from here, not findutils.

[onomatopellan]

That makes sense, thanks!

[therealkenc]

That's a good place to send a PR, were someone motivated. It would make its way downstream eventually.