Temporary fix to make Fred.app work against older macOS versions

fred-macos.md

To make Fred.app work on macOS versions before Tahoe you will need LLVM 20+.

You can grab it either through Homebrew (easiest, brew install llvm), from GitHub (https://github.com/llvm/llvm-project/releases) or from their official site (https://releases.llvm.org/)

Note down the path where you installed it. In case of Homebrew you can run brew --prefix llvm to get the path.

Then continue to download Fred.dmg from Dropbox, and move the Fred.app into a user folder (i.e. ~/Downloads)

Next, open a terminal and change to the folder you put Fred.app in

cd ~/Downloads

Remove the quarantine attributes from the application.

xattr -rd com.apple.quarantine ~/Downloads/Fred.app

Next, we change the paths to point libc++ against the LLVM you installed:

install_name_tool -change /usr/lib/libc++.1.dylib /opt/homebrew/opt/llvm/lib/c++/libc++.1.dylib ./Fred.app/Contents/MacOS/fred

Keep the first path as-is, as this is the one we need to replace. The second path is the path to the LLVM, this depends how you installed it.

Next, we change the build version info of the binary. You can set this to whatever macOS version you have (i.e. 15.0 for Seqoia)

vtool -set-build-version macos 15.0 15.7 -output ./Fred.app/Contents/MacOS/fred ./Fred.app/Contents/MacOS/fred

After all that we just re-sign the application binaries with an ad-hoc code signature. This will overwrite existing signatures, which is required as we changed the binary.

codesign --force --deep --sign - ./Fred.app

You can move Fred.app into /Applications at this point.