WSL2 install - plutus fails to build, unable to open db file in 'nix/var/nix/db/db.sqlite'

Question

I'm attempting to finish the setup for plutus pioneers cohort3 on wsl2 (Windows 10) with Ubunutu 20.04. When I run the command:

nix --extra-experimental-features nix-command build -f default.nix plutus.haskell.packages.plutus-core.components.library

I get:

error: executing SQLite statement 'pragma synchronous = normal': unable to open database file (in '/nix/var/nix/db/db.sqlite')

I have already created /etc/nix/nix.conf to configure nix with the IOHK binary cache. I also checked and there is no var folder within the nix directory. Did I fail to create a db along the way or is something else amiss?

Answer 1

I had this problem yesterday and I found that shutting down the distro and restarting it after installing nix worked to fix this issue, it may work for you as well.

• Exit out of the ubuntu distro
• In a windows terminal (powershell or whatever) use wsl -l -v to see the running distros
• Then use wsl --terminate <DistributionName> to stop the distro
• Then use wsl --distribution <DistributionName> to start the distro again
• Now you can try to build again.

Here's where I found the wsl commands - https://winaero.com/terminate-running-wsl-linux-distro-windows-10/

On another note you should be using the plutus-apps repo not the plutus repo. Here's a link to a doc from another pioneer who setup the environemnt with WSL that may help you - https://docs.google.com/document/d/1mLyuGmCvZLqFotpVElbhYR5Q6PUatGxSeGuulJ1izJA/edit

Answer 2

deleting the /nix/var directory

and then running

nix build -f default.nix docs.site --extra-experimental-features nix-command

fixed the

error: executing SQLite statement 'pragma synchronous = normal': unable to open database file (in '/nix/var/nix/db/db.sqlite')

error for me.

Answer 3

I had success by uninstalling/removing Nix, and then installing it again

Uninstalling:

1. remove the . "$HOME/.nix-profile/etc/profile.d/nix.sh" line in your ~/.profile or ~/.bash_profile
2. rm -rf $HOME/{.nix-channels,.nix-defexpr,.nix-profile,.config/nixpkgs}
3. sudo rm -rf /nix

Reinstalling:

1. sh <(curl -L https://nixos.org/nix/install) --no-daemon
2. . $HOME/.nix-profile/etc/profile.d/nix.sh

Answer 4

You need to change the permissions on your /nix directory.

If you run this command you should be able to move forward:

chmod 775 /nix