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Troubleshooting

This document intends to record frequently occurring issues running our Nix setup and how to fix them. Please note that this list is not exhaustive and only suggests some known fixes that may not apply to your issue.

No space left on device

LLVM ERROR: IO failure on output stream: No space left on device

If you encounter a No space left on device error even though enough disk space is available, we need to increase the maximum size of your /tmp directory.

You can achieve this one of two ways:

1. Temporary fix

To fix the issue temporarily, use the following command as root user.

$ mount -o remount,size=16G /tmp/

This command will remount the /tmp directory with an increased size of up to 16Gb.

2. Permanent fix

To fix this issue permanently, we need to edit the /etc/fstab file using a text editor of your choice.

Look for a line starting with tmpfs and update it like the following, or append it to the bottom if it doesn't exist yet.

$ tmpfs /tmp tmpfs rw,nodev,nosuid,size=16G 0 0

This change will permanently mount the /tmp directory with a fixed size of 16Gb.

Too many open files

If you encounter a Too many open files error, this limit needs to be increased.

The easiest way is to modify the run command with the ulimit command. Like the following:

$ bash -c 'ulimit -n 10000; nix run github:composablefi/composable#devnet-dali`

Nix run command does not respect nix.conf configuration.

If you're running Nix on a non-NixOS Linux distribution, even if your config file(s) are set up correctly, you may encounter some or all of the following issues:

experimental Nix feature is disabled. 
error: derivation '/nix/store/some-derivation.drv' has '__noChroot' set, but that's not allowed when 'sandbox' is 'true'

This is due to Nix not reading the config file. Following are some possible solutions:

Restart Nix Daemon

Restarting the nix-daemon may resolve this:

$ systemctl restart nix-daemon

Move nix.conf

The Nix configuration directory may need to be changed to /etc/nix/nix.conf, instead of ~/.config/nix/nix.conf. See the installation process for more details.

Can't re-install Nix after macOS update

To successfully re-install Nix after a macOS update, you need to remove the existing /nix directory, and start the installer again.

The following command removes the /nix directory.

$ sudo rm -rf /nix