Installation¶

For most users we recommend installing the release version of Finesse as this will always be the most stable. Any bugs found in release versions can be debugged more easily than in an arbitrary development version, so subsequent minor releases will typically address these issues faster.

Release version¶

Finesse 3 is still under active development. There is currently no release version available. You can find the executables for the stable Finesse 2 at: http://www.gwoptics.org/finesse.

From source¶

Note

If you want to contribute to the development of Finesse then you should read Getting started with Finesse development as this will tell you how to set-up a development environment which is separate to any stable version you may have installed.

Follow the steps below to install the latest state of Finesse. Make sure to follow the guide corresponding to the system you are installing to.

Linux / Mac OSX / WSL¶

If you have not already done so, install the Conda package manager.
Install gcc. If you are on Debian/Ubuntu or similar, install via:
```
apt-get install build-essential
```
Or if you are on a Mac:
```
xcode-select --install
```

Clone the repository https://git.ligo.org/finesse/finesse3 via HTTPS:

git clone https://git.ligo.org/finesse/finesse3

Or via SSH:

git clone git@git.ligo.org:finesse/finesse3.git

Change directory to your local copy of the Finesse repository:
```
cd finesse3
```
Create a new Conda environment using the Finesse environment file:
```
conda env create -n <name_of_environment> -f environment.yml
```
where you should substitute <name_of_environment> for a suitable name of your choice, e.g: finesse3.
The above step should automatically activate your new environment, but to make sure that your shell is using this Conda environment from above run:
```
conda activate <name_of_environment>
```
Installation of Finesse in development mode is now simple, just run:
```
pip install -e .
```
in the root directory of your local copy of the Finesse repository.

Windows¶

If you have not already done so, install the Conda package manager.
Again, if you have not already done so, install Git for Windows. You can either use the tools this provides directly to clone the Finesse repository (see step 5 below) or add the path to your git executable to the Windows environment variables - details on how to do this are shown in the next step, but you can skip this if you intend to use the git bash/gui here feature(s) of Git for Windows.
(Optional) To be able to use git from the command line, and via an Anaconda Prompt, you need to add the path to your git executable (installed in the step above) to the Windows environment variables.

Type “environment variables” into the Windows search bar and open the first result. Click the “Environment Variables…” button.

In the new window that pops up, navigate to the lower panel (System Variables) and find the field named “Path”. Click the “Edit” button with this field highlighted. You will now be presented with a window showing all the currently stored paths. Click the “New” button in this Window and add the following two paths separately:
```
C:\Program Files\Git\bin\git.exe
C:\Program Files\Git\cmd
```
Note that these paths above are assuming that you did not change the default install location of Git for Windows in step 2.
Open an Anaconda Prompt using the Windows search bar.
Clone the repository https://git.ligo.org/finesse/finesse3 via HTTPS:
```
git clone https://git.ligo.org/finesse/finesse3
```
Or via SSH:
```
git clone git@git.ligo.org:finesse/finesse3.git
```
Note that if you skipped step 3 then you will need to use git bash here or git gui here by right clicking in the File Explorer. If you select git bash here then you will be presented with a bash-like terminal in which you can run the git clone command above. Close this terminal after cloning the repository and return to your Anaconda Prompt.
Change directory to your local copy of the Finesse repository:
```
cd finesse3
```
Create a new Conda environment using the Finesse Windows environment file:
```
conda env create -n <name_of_environment> -f environment_win.yml
```
where you should substitute <name_of_environment> for a suitable name of your choice, e.g: finesse3.
The above step should automatically activate your new environment, but to make sure that your shell is using this Conda environment from above run:
```
conda activate <name_of_environment>
```
To build the Cython extensions of Finesse you must now run:
```
make.bat
```
Installation of Finesse in development mode is now simple, just run:
```
pip install -e .
```
in the root directory of your local copy of the Finesse repository.

If you encounter any issues here then refer to the troubleshooting guide below.

Note that in the final step of both guides above we use the -e option with pip install. This options means that the install is performed in “editable” mode such that any changes to Python source code files in Finesse (i.e. after pulling the latest changes on master from the repository) will be reflected in a version installed in this way.

Keeping your development version up to date¶

If you want to use all the new features of Finesse as they are developed then you will need to pull changes from the repository as and when you need them. To do this, simply run:

git pull

when in any directory of your local copy of the Finesse repository. If the changes include any modifications to (or additions / deletions of) .pyx / .pxd files then you will need to re-build the Cython extensions. On Linux / MacOS this means just repeating step 6 whilst on Windows you should repeat step 9, from the above guides.

Troubleshooting installation from source on Windows¶

A number of different errors may occur when attempting to install Finesse from source on Windows. The list below should be a comprehensive guide to addressing these issues.

I’m getting the following error during the compilation process for the Cython extensions: cannot find -lmsvcr140.

Here are the steps to resolve this error:

Use the Windows search bar to find a vcruntime140.dll file. Open the folder location of this file and copy the file.
Paste this file to: C:\<ANACONDA_PATH>\envs\<ENV_NAME>\Library\mingw-w64\lib where <ANACONDA_PATH> is the path to your Conda installation and <ENV_NAME> is the name of your Conda environment that you are using for your Finesse installation.

If you still get this error after the steps above, then use the Windows search bar to find the file cygwinccompiler.py. Open this file and edit the following lines, from this:

elif int(msc_ver) >= 1900:
    # VS2015 / MSVC 14.0
    return ['msvcr140']

to this:

elif int(msc_ver) >= 1900:
    # VS2015/ MSVC 14.0
    return ['vcruntime140']