nixpkgs/pkgs/development/python-modules/graphviz/hardcode-graphviz-path.patch

diff --git a/graphviz/backend.py b/graphviz/backend.py
index 704017b..fe4aefe 100644
--- a/graphviz/backend.py
+++ b/graphviz/backend.py
@@ -114,7 +114,7 @@ def command(engine, format, filepath=None, renderer=None, formatter=None):
     suffix = '.'.join(reversed(format_arg))
     format_arg = ':'.join(format_arg)
 
-    cmd = [engine, '-T%s' % format_arg]
+    cmd = [os.path.join('@graphviz@/bin', engine), '-T%s' % format_arg]
     rendered = None
     if filepath is not None:
         cmd.extend(['-O', filepath])
@@ -217,7 +217,7 @@ def version():
         subprocess.CalledProcessError: If the exit status is non-zero.
         RuntimmeError: If the output cannot be parsed into a version number.
     """
-    cmd = ['dot', '-V']
+    cmd = ['@graphviz@/bin/dot', '-V']
     out, _ = run(cmd, check=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
 
     info = out.decode('ascii')
diff --git a/tests/test_backend.py b/tests/test_backend.py
index 7ec12f7..2e8550d 100644
--- a/tests/test_backend.py
+++ b/tests/test_backend.py
@@ -47,6 +47,7 @@ def test_render_formatter_unknown():
         render('dot', 'ps', 'nonfilepath', 'ps', '')
 
 
+@pytest.mark.skip(reason='empty $PATH has no effect')
 @pytest.mark.usefixtures('empty_path')
 def test_render_missing_executable():
     with pytest.raises(ExecutableNotFound, match=r'execute'):
@@ -85,7 +86,7 @@ def test_render_mocked(capsys, mocker, Popen, quiet):
 
     assert render('dot', 'pdf', 'nonfilepath', quiet=quiet) == 'nonfilepath.pdf'
 
-    Popen.assert_called_once_with(['dot', '-Tpdf', '-O', 'nonfilepath'],
+    Popen.assert_called_once_with(['@graphviz@/bin/dot', '-Tpdf', '-O', 'nonfilepath'],
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE,
                                   startupinfo=mocker.ANY)
@@ -94,6 +95,7 @@ def test_render_mocked(capsys, mocker, Popen, quiet):
     assert capsys.readouterr() == ('', '' if quiet else 'stderr')
 
 
+@pytest.mark.skip(reason='empty $PATH has no effect')
 @pytest.mark.usefixtures('empty_path')
 def test_pipe_missing_executable():
     with pytest.raises(ExecutableNotFound, match=r'execute'):
@@ -143,7 +145,7 @@ def test_pipe_pipe_invalid_data_mocked(mocker, py2, Popen, quiet):  # noqa: N803
     assert e.value.returncode is mocker.sentinel.returncode
     assert e.value.stdout is mocker.sentinel.out
     assert e.value.stderr is err
-    Popen.assert_called_once_with(['dot', '-Tpng'],
+    Popen.assert_called_once_with(['@graphviz@/bin/dot', '-Tpng'],
                                   stdin=subprocess.PIPE,
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE,
@@ -166,7 +168,7 @@ def test_pipe_mocked(capsys, mocker, Popen, quiet):  # noqa: N803
 
     assert pipe('dot', 'png', b'nongraph', quiet=quiet) is mocker.sentinel.out
 
-    Popen.assert_called_once_with(['dot', '-Tpng'],
+    Popen.assert_called_once_with(['@graphviz@/bin/dot', '-Tpng'],
                                   stdin=subprocess.PIPE,
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE,
@@ -176,6 +178,7 @@ def test_pipe_mocked(capsys, mocker, Popen, quiet):  # noqa: N803
     assert capsys.readouterr() == ('', '' if quiet else 'stderr')
 
 
+@pytest.mark.skip(reason='empty $PATH has no effect')
 @pytest.mark.usefixtures('empty_path')
 def test_version_missing_executable():
     with pytest.raises(ExecutableNotFound, match=r'execute'):
@@ -196,7 +199,7 @@ def test_version_parsefail_mocked(mocker, Popen):
     with pytest.raises(RuntimeError):
         version()
 
-    Popen.assert_called_once_with(['dot', '-V'],
+    Popen.assert_called_once_with(['@graphviz@/bin/dot', '-V'],
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.STDOUT,
                                   startupinfo=mocker.ANY)
@@ -211,7 +214,7 @@ def test_version_mocked(mocker, Popen):
 
     assert version() == (1, 2, 3)
 
-    Popen.assert_called_once_with(['dot', '-V'],
+    Popen.assert_called_once_with(['@graphviz@/bin/dot', '-V'],
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.STDOUT,
                                   startupinfo=mocker.ANY)