title: MacOS: brew install graph-tool on High Sierra
body: <p>I'm using High Sierra and am unable to install graph-tool via brew install. Given below is the output after brew installing. </p>
  
  <pre><code>&gt; brew install graph-tool
  graph-tool: macOS Mojave or newer is required.
  Error: An unsatisfied requirement failed this build.
  </code></pre>
  
  <p>As I'm using a somewhat locked down machine, I'm unable to update to Mojave. I've previously been able to <code>brew install graph-tool</code> on High Sierra without issues. </p>
  
  <p>The <a href="https://formulae.brew.sh/formula/graph-tool" rel="nofollow noreferrer">homebrew formulae link for graph-tool</a> seems to state that it's only available for Mojave now. As does the formula itself.</p>
  
  <p><a href="https://github.com/Homebrew/homebrew-core/blob/master/Formula/graph-tool.rb" rel="nofollow noreferrer">https://github.com/Homebrew/homebrew-core/blob/master/Formula/graph-tool.rb</a></p>
  
  <p><code>depends_on :macos =&gt; :mojave # for C++17</code></p>
  
  <p>Is there a way I can install an older version of graph-tool on my machine? </p>
  
  <hr>
  
  <p><strong>Update</strong></p>
  
  <p>This might not apply to most people. But since it was such effort installing graph_tool I thought I'd copy my solution here.</p>
  
  <p>When trying bfontaine's solution, I kept getting the following error:</p>
  
  <pre><code>==&gt; /usr/local/Cellar/graph-tool/2.27_7/libexec/bin/pip install -v --no-deps --no-binary :all: --ignore-installed /private/tmp/graph-tool--matplotlib-20190621-40984-1767uhv/matplotlib-2.2.2
  
  Last 15 lines from /Users/greatora/Library/Logs/Homebrew/graph-tool/05.pip:
  Removed build tracker '/private/tmp/pip-req-tracker-b74drkg2'
  ERROR: Command "/usr/local/Cellar/graph-tool/2.27_7/libexec/bin/python3.7 -u -c 'import setuptools, tokenize;__file__='"'"'/private/tmp/pip-req-build-6ib3tzd9/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /private/tmp/pip-record-8ubg3x4_/install-record.txt --single-version-externally-managed --compile --install-headers /usr/local/Cellar/graph-tool/2.27_7/libexec/bin/../include/site/python3.7/matplotlib" failed with error code 1 in /private/tmp/pip-req-build-6ib3tzd9/
  Exception information:
  Traceback (most recent call last):
    File "/usr/local/Cellar/graph-tool/2.27_7/libexec/lib/python3.7/site-packages/pip/_internal/cli/base_command.py", line 178, in main
      status = self.run(options, args)
    File "/usr/local/Cellar/graph-tool/2.27_7/libexec/lib/python3.7/site-packages/pip/_internal/commands/install.py", line 414, in run
      use_user_site=options.use_user_site,
    File "/usr/local/Cellar/graph-tool/2.27_7/libexec/lib/python3.7/site-packages/pip/_internal/req/__init__.py", line 58, in install_given_reqs
      **kwargs
    File "/usr/local/Cellar/graph-tool/2.27_7/libexec/lib/python3.7/site-packages/pip/_internal/req/req_install.py", line 951, in install
      spinner=spinner,
    File "/usr/local/Cellar/graph-tool/2.27_7/libexec/lib/python3.7/site-packages/pip/_internal/utils/misc.py", line 776, in call_subprocess
      % (command_desc, proc.returncode, cwd))
  pip._internal.exceptions.InstallationError: Command "/usr/local/Cellar/graph-tool/2.27_7/libexec/bin/python3.7 -u -c 'import setuptools, tokenize;__file__='"'"'/private/tmp/pip-req-build-6ib3tzd9/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /private/tmp/pip-record-8ubg3x4_/install-record.txt --single-version-externally-managed --compile --install-headers /usr/local/Cellar/graph-tool/2.27_7/libexec/bin/../include/site/python3.7/matplotlib" failed with error code 1 in /private/tmp/pip-req-build-6ib3tzd9/
  </code></pre>
  
  <p>I realised that I won't be using graph-tool's (excellent) functionality for visualisation, so I downloaded the graph_tool.rb file that bfontaine linked below, cut the matplotlib dependency from it, and ran <code>brew install --build-from-source ~/Downloads/graph-tool.rb</code>. </p>
  
  <p>I then downgraded numpy to 1.16.1, and graph_tool works as expected!</p>
  
  <p>Again, <strong>only do this if you don't plan on using graph_tool's visualisation capabilities</strong>.</p>
  
  <p>See below for my modifed graph_tool.rb file.</p>
  
  <pre><code>class GraphTool &lt; Formula
    include Language::Python::Virtualenv
  
    desc "Efficient network analysis for Python 3"
    homepage "https://graph-tool.skewed.de/"
    url "https://downloads.skewed.de/graph-tool/graph-tool-2.27.tar.bz2"
    sha256 "4740c69720dfbebf8fb3e77057b3e6a257ccf0432cdaf7345f873247390e4313"
    revision 7
  
    bottle do
      sha256 "4bf2967b707d3fa33dbb1d0f54d2cf18b33820754232883f9f53192dd1155ccc" =&gt; :mojave
      sha256 "7454e5ac93d90e1e0048df7e34e6069e36674597d495fb76e2a22494f5fb76c1" =&gt; :sierra
    end
  
    depends_on "pkg-config" =&gt; :build
    depends_on "boost"
    depends_on "boost-python3"
    depends_on "cairomm"
    depends_on "cgal"
    depends_on "google-sparsehash"
    depends_on "gtk+3"
    depends_on "librsvg"
    depends_on :macos =&gt; :el_capitan # needs thread-local storage
    depends_on "numpy"
    depends_on "py3cairo"
    depends_on "pygobject3"
    depends_on "python"
    depends_on "scipy"
  
    resource "Cycler" do
      url "https://files.pythonhosted.org/packages/c2/4b/137dea450d6e1e3d474e1d873cd1d4f7d3beed7e0dc973b06e8e10d32488/cycler-0.10.0.tar.gz"
      sha256 "cd7b2d1018258d7247a71425e9f26463dfb444d411c39569972f4ce586b0c9d8"
    end
  
    resource "kiwisolver" do
      url "https://files.pythonhosted.org/packages/31/60/494fcce70d60a598c32ee00e71542e52e27c978e5f8219fae0d4ac6e2864/kiwisolver-1.0.1.tar.gz"
      sha256 "ce3be5d520b4d2c3e5eeb4cd2ef62b9b9ab8ac6b6fedbaa0e39cdb6f50644278"
    end
  
    resource "pyparsing" do
      url "https://files.pythonhosted.org/packages/3c/ec/a94f8cf7274ea60b5413df054f82a8980523efd712ec55a59e7c3357cf7c/pyparsing-2.2.0.tar.gz"
      sha256 "0832bcf47acd283788593e7a0f542407bd9550a55a8a8435214a1960e04bcb04"
    end
  
    resource "python-dateutil" do
      url "https://files.pythonhosted.org/packages/a0/b0/a4e3241d2dee665fea11baec21389aec6886655cd4db7647ddf96c3fad15/python-dateutil-2.7.3.tar.gz"
      sha256 "e27001de32f627c22380a688bcc43ce83504a7bc5da472209b4c70f02829f0b8"
    end
  
    resource "pytz" do
      url "https://files.pythonhosted.org/packages/10/76/52efda4ef98e7544321fd8d5d512e11739c1df18b0649551aeccfb1c8376/pytz-2018.4.tar.gz"
      sha256 "c06425302f2cf668f1bba7a0a03f3c1d34d4ebeef2c72003da308b3947c7f749"
    end
  
    resource "six" do
      url "https://files.pythonhosted.org/packages/16/d8/bc6316cf98419719bd59c91742194c111b6f2e85abac88e496adefaf7afe/six-1.11.0.tar.gz"
      sha256 "70e8a77beed4562e7f14fe23a786b54f6296e34344c23bc42f07b15018ff98e9"
    end
  
    # Remove for &gt; 2.27
    # Upstream commit from 3 Jul 2018 "Fix incompatibility with Python 3.7"
    patch do
      url "https://git.skewed.de/count0/graph-tool/commit/0407f41a.diff"
      sha256 "94559544ad95753a13ee701c02af706c8b296c54af2c1706520ec96e24aa6d39"
    end
  
    # Remove for &gt; 2.27
    # Upstream commit from 3 Oct 2018 "Fix compilation with CGAL 4.13"
    patch do
      url "https://git.skewed.de/count0/graph-tool/commit/aa39e4a6.diff"
      sha256 "5a4ea386342c2de9422da5b07dd4272d47d2cdbba99d9b258bff65a69da562c1"
    end
  
    def install
      # Work around "error: no member named 'signbit' in the global namespace"
      ENV["SDKROOT"] = MacOS.sdk_path if MacOS.version == :high_sierra
  
      xy = Language::Python.major_minor_version "python3"
      venv = virtualenv_create(libexec, "python3")
  
      resources.each do |r|
        venv.pip_install_and_link r
      end
  
      args = %W[
        --disable-debug
        --disable-dependency-tracking
        --prefix=#{prefix}
        PYTHON=python3
        PYTHON_LIBS=-undefined\ dynamic_lookup
        --with-python-module-path=#{lib}/python#{xy}/site-packages
        --with-boost-python=boost_python#{xy.to_s.delete(".")}-mt
      ]
      args &lt;&lt; "--with-expat=#{MacOS.sdk_path}/usr" if MacOS.sdk_path_if_needed
  
      system "./configure", *args
      system "make", "install"
  
      site_packages = "lib/python#{xy}/site-packages"
      pth_contents = "import site; site.addsitedir('#{libexec/site_packages}')\n"
      (prefix/site_packages/"homebrew-graph-tool.pth").write pth_contents
    end
  
    test do
      (testpath/"test.py").write &lt;&lt;~EOS
        import graph_tool as gt
        g = gt.Graph()
        v1 = g.add_vertex()
        v2 = g.add_vertex()
        e = g.add_edge(v1, v2)
        assert g.num_edges() == 1
        assert g.num_vertices() == 2
      EOS
      system "python3", "test.py"
    end
  end
  </code></pre>