[4.6] Improve output when parsing an ini configuration fails (#… (#5652)

[4.6] Improve output when parsing an ini configuration fails (#5650)

.travis.yml

@@ -13,6 +13,10 @@ env:
   global:
     - PYTEST_ADDOPTS=-vv
 
+# setuptools-scm needs all tags in order to obtain a proper version
+git:
+  depth: false
+
 install:
   - python -m pip install --upgrade --pre tox
 

changelog/5650.bugfix.rst

@@ -0,0 +1 @@
+Improved output when parsing an ini configuration file fails.

src/_pytest/config/findpaths.py

@@ -33,7 +33,11 @@ def getcfg(args, config=None):
             for inibasename in inibasenames:
                 p = base.join(inibasename)
                 if exists(p):
-                    iniconfig = py.iniconfig.IniConfig(p)
+                    try:
+                        iniconfig = py.iniconfig.IniConfig(p)
+                    except py.iniconfig.ParseError as exc:
+                        raise UsageError(str(exc))
+
                     if (
                         inibasename == "setup.cfg"
                         and "tool:pytest" in iniconfig.sections

testing/test_config.py

@@ -131,6 +131,12 @@ class TestParseIni(object):
         config = testdir.parseconfigure(sub)
         assert config.getini("minversion") == "2.0"
 
+    def test_ini_parse_error(self, testdir):
+        testdir.tmpdir.join("pytest.ini").write("addopts = -x")
+        result = testdir.runpytest()
+        assert result.ret != 0
+        result.stderr.fnmatch_lines(["ERROR: *pytest.ini:1: no section header defined"])
+
     @pytest.mark.xfail(reason="probably not needed")
     def test_confcutdir(self, testdir):
         sub = testdir.mkdir("sub")