Install on macOS

The most convenient way to install COSEDA (and its dependency CrystFEL) is to use the Homebrew package manager. The installation is done in 3 simple steps via the command line.

Installing Homebrew (skip if already using Homebrew)

1) Install Xcode Command Line Tools

xcode-select --install

2) Install Homebrew

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

3) Add Homebrew to you shell

For Apple Silicon Macs

echo 'eval "$(/opt/homebrew/bin/brew shellenv)"' >> ~/.zprofile
eval "$(/opt/homebrew/bin/brew shellenv)"

For Intel Macs

echo 'eval "$(/usr/local/bin/brew shellenv)"' >> ~/.zprofile
eval "$(/usr/local/bin/brew shellenv)"

If you are unsure which one you have click on the Apple logo in the Menu bar -> About This Mac -> Chip.

4) Check

brew --version
brew doctor

Congrats, this was the hardest part.

Installing COSEDA

1) Add the tap

This tells Homebrew where it can find the source of COSEDA.

brew tap kristallorakel/coseda https://gitlab.com/kristallorakel/homebrew-coseda.git

2) Install

brew install coseda

Optional: install the nightly build

The nightly build contains beta changes from the development branch. It is useful for testing new features, but it may be less stable than the regular release.

brew install coseda-nightly

The stable and nightly formulas both install the coseda command and COSEDA.app, so Homebrew will not install them side by side. To switch between them:

brew uninstall coseda
brew install coseda-nightly

or:

brew uninstall coseda-nightly
brew install coseda

3) Run

If the installation was successful, you can run COSEDA via a simple command. Running it for the first time might take a moment, please be patient.

coseda

Update

COSEDA checks for updates automatically on startup and will prompt you to upgrade with a single button click.

If you prefer to update manually from the terminal:

brew upgrade coseda

Troubleshooting: “Cannot install under Rosetta 2”

If the in-app update fails with a Rosetta 2 error, macOS has incorrectly marked COSEDA to run under x86_64 emulation. To fix it:

  1. Right-click COSEDA.app in Finder → Get Info

  2. Uncheck Open using Rosetta

  3. Relaunch COSEDA — the update button will now work

Alternatively, run the upgrade once from a terminal:

brew upgrade coseda

This is a one-time fix. Newer installations are not affected.

Installing CrystFEL

CrystFEL is COSEDA’s most important dependency. Similarly, you can install it using homebrew:

brew tap desy/crystfel https://gitlab.desy.de/thomas.white/homebrew-crystfel
brew install crystfel