在macOS上安装ocaml-top遇到GTK相关问题

Hey there! Let's work through that frustrating error you're seeing when trying to install ocaml-top. The conf-gtksourceview.2 failure happens because Opam can't find the GTKSourceView 2 library on your system—and since macOS High Sierra is an older release, the default Homebrew packages might not include this version anymore. Here are step-by-step fixes to get this sorted:

1. Install GTKSourceView 2 via Homebrew #

First, we need to get the required GTKSourceView 2 library onto your system. Since the standard gtksourceview formula now defaults to newer versions, we'll install the legacy 2.x variant:

• Update Homebrew first (even on High Sierra, this should still work for older packages):

  brew update
  

• Install the GTKSourceView 2.x package:

  brew install gtksourceview@2
  

• If the above command throws an error about the formula being unavailable, you can manually grab an older version of the gtksourceview formula that supports High Sierra:
  1. Locate a commit in the Homebrew Core formula history for gtksourceview that targets version 2.x and is compatible with macOS 10.13.
  2. Download the gtksourceview.rb file from that commit.
  3. Install it locally with:

     brew install ./gtksourceview.rb
     

2. Tell Opam Where to Find the Library #

Once GTKSourceView 2 is installed, we need to make sure Opam's conf-gtksourceview.2 check can locate it. Set the PKG_CONFIG_PATH environment variable to point to the library's pkgconfig files:

• First, confirm the installation path with:

  brew info gtksourceview@2
  

  Look for a line like /usr/local/opt/gtksourceview@2—this is the base path.
• Export the path to your shell session:

  export PKG_CONFIG_PATH="/usr/local/opt/gtksourceview@2/lib/pkgconfig:$PKG_CONFIG_PATH"
  

• Re-run the Opam install command:

  opam install ocaml-top
  

3. Fallback: Downgrade Opam for Compatibility #

If the above steps still fail, it might be because newer Opam versions aren't fully compatible with macOS High Sierra. Try downgrading to Opam 2.0.x:

• Uninstall your current Opam:

  brew uninstall opam
  

• Install the legacy Opam 2.0 package:

  brew install opam@2.0
  

• Link it to make it the default Opam:

  brew link --force opam@2.0
  

• Re-initialize Opam (you can keep your existing setup when prompted):

  opam init
  eval `opam config env`
  

• Now try installing ocaml-top again:

  opam install ocaml-top
  

These steps should resolve the conf-gtksourceview.2 failure by either providing the missing library or ensuring Opam plays nicely with your older macOS release.

内容的提问来源于stack exchange，提问作者Jean