Use gethostname instead of potentially slow getfqdn

This avoid bug that is adding 30s on some machines where getfqdn()
is very slow, as this is caused by an unsolved python bug.

Related: https://bugs.python.org/issue35164
Fixes: #2375

docs/changelog/2375.bugfix.rst

@@ -0,0 +1 @@
+Avoid potential 30s delay caused by socket.getfqdn(). -- by :user:`ssbarnea`

src/tox/logs/result.py

@@ -22,7 +22,7 @@ def __init__(self):
             "reportversion": "1",
             "toxversion": __version__,
             "platform": sys.platform,
-            "host": os.getenv(str("HOSTNAME")) or socket.getfqdn(),
+            "host": os.getenv(str("HOSTNAME")) or socket.gethostname(),
             "commands": command_log,
         }
 

tests/unit/test_result.py

@@ -31,7 +31,7 @@ def test_pre_set_header(clean_hostname_envvar):
     assert replog.dict["reportversion"] == "1"
     assert replog.dict["toxversion"] == tox.__version__
     assert replog.dict["platform"] == sys.platform
-    assert replog.dict["host"] == socket.getfqdn()
+    assert replog.dict["host"] == socket.gethostname()
     data = replog.dumps_json()
     replog2 = ResultLog.from_json(data)
     assert replog2.dict == replog.dict
@@ -44,7 +44,7 @@ def test_set_header(pkg, clean_hostname_envvar):
     assert replog.dict["reportversion"] == "1"
     assert replog.dict["toxversion"] == tox.__version__
     assert replog.dict["platform"] == sys.platform
-    assert replog.dict["host"] == socket.getfqdn()
+    assert replog.dict["host"] == socket.gethostname()
     expected = {"basename": "hello-1.0.tar.gz", "sha256": pkg.computehash("sha256")}
     env_log = replog.get_envlog("a")
     env_log.set_header(installpkg=pkg)