How do I modify a Homebrew formula?

Question

I installed ImageMagick via Homebrew. However, due to a bug I have with my current configuration, I need to adjust the compile flags for the formula and reinstall it. How can I accomplish this?

Accepted Answer

Remove the existing version.

```
$ brew rm imagemagick
```

Edit the formula.

```
$ brew edit imagemagick
```

This will bring it up in an editor; make sure your `$EDITOR` variable is set to your preference (for me: TextMate)

Change it, save it, try re-installing it.

Because most installs use pouring/bottles to install a precompiled binary, you will likely see no change unless you "build from source":

```
$ brew reinstall --build-from-source [...]
```

You can use `--formula /path/to/imagemagick.rb` as an additional argument to the above command to ensure `brew` is installing the formula that was edited.

If you're comfortable with git, you may also want to make a branch first, and do your edits in a branch to guard against data loss.

How do I modify a Homebrew formula?

Solution

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