Installing a specific version of nRF Util

During development, you want to use the latest version of nRF Util installed from the web together with the latest version of the nRF Util commands.

In other cases, for example when setting up production or CI environments, you might want to install a specific version of nRF Util. For this purpose, you need to download earlier versions of the nrfutil executable and the nRF Util core module, and point the executable to the desired core module version tarball file.

Complete the following steps:

Make sure nRF Util is not installed on the machine you are using.
Download a specific version of the nrfutil executable:
1. Open the files.nordicsemi.com hosting website.
2. Go to the directory for your operating system.
3. Download the specific version of the nrfutil executable. The unversioned executable is always the same as the latest versioned nrfutil file.
Download the tarball for the desired version of the nRF Util core module from the nRF Util core modules list on files.nordicsemi.com.
Set the NRFUTIL_BOOTSTRAP_TARBALL_PATH environment variable to the full path of the downloaded tarball:
```
export NRFUTIL_BOOTSTRAP_TARBALL_PATH=/home/user/files/<file_name>.tar.gz
```
For example, if you want to install version 7.14.0 of the nRF Util core module for Linux x64, use the following command:
```
export NRFUTIL_BOOTSTRAP_TARBALL_PATH=/home/user/files/nrfutil-x86_64-unknown-linux-gnu-7.14.0.tar.gz
```
Check the environment variable setting and the version of the core module by running the following command:
```
nrfutil --version
```
The output should match the version of the core module you downloaded.

When you run this command, nRF Util detects the presence of the environment variable. However, it also installs the core functionality from the indicated tarball instead of finding the latest core package online. For this reason, if the output version does not match the version of the core module you downloaded, complete the following steps:
1. Make sure to set the NRFUTIL_BOOTSTRAP_TARBALL_PATH environment variable correctly.
2. Delete the .nrfutil directory.
  
  Tip
  
  If you have created custom configuration files for nRF Util, make a backup of the .nrfutil/config directory before deleting it.
3. Re-run the nrfutil --version command.

You now have a specific version of the nRF Util executable and a specific version of the core package installed. To install a specific version of the nRF Util commands, see Installing specific versions of commands.