Attempt to fix timeout issue on Travis. (#16979)

* Attempt to fix timeout issue on Travis.

* Revert "Attempt to fix timeout issue on Travis."

This reverts commit a4e399efab.

* Attempt 2: asyncio galore.

* Guess we don't get to use 3.6

* Guess we don't get to use 3.5

* Dumb mistakes galore

* How did I even manage this?

* Guess we don't get to use 3.4.4

* Hey it works, reduce verbosity a bit.

* asyncio.coroutine.

Technically not needed since asyncio can do without and just screams into a logger if you don't.

* Even less verbose. Shouldn't trigger anymore except for problem cases.

tools/travis/build.py

@@ -1,15 +1,21 @@
-#!/usr/bin/env python
-from __future__ import print_function, unicode_literals
+#!/usr/bin/env python3
 import argparse
-import re
+import asyncio
 import distutils.spawn
-import os
+import re
 import sys
 
-try:    
-    import subprocess32 as subprocess
-except ImportError:
-    import subprocess
+MAP_INCLUDE_RE = re.compile(r"#include \"maps\\[a-zA-Z0-9][a-zA-Z0-9_]*\.dm\"")
+
+ensure_future = None
+
+# ensure_future is new in 3.4.4, previously it was asyncio.async.
+try:
+    ensure_future = asyncio.ensure_future
+except AttributeError:
+    # Can't directly do asyncio.async because async is a keyword now,
+    # and that'd parse error on newer versions.
+    ensure_future = getattr(asyncio, "async")
 
 
 def main():
@@ -23,18 +29,17 @@ def main():
         # Handle map file replacement.
         with open(dme, "r") as f:
             content = f.read()
-        
+
         # Make string to replace the map include with.
         includes = ""
         for arg in args.mapfile:
             includes += "#include \"maps\\\\{}.dm\"\n".format(arg)
-        
-        MAP_INCLUDE_RE = re.compile(r"#include \"maps\\[a-zA-Z0-9][a-zA-Z0-9_]*\.dm\"")
+
         content = MAP_INCLUDE_RE.sub(includes, content, count=1)
         dme = "{}.mdme".format(dme)
         with open(dme, "w") as f:
             f.write(content)
-    
+
     compiler = "DreamMaker"
     if sys.platform == "win32" or sys.platform == "cygwin":
         compiler = "dm"
@@ -44,8 +49,28 @@ def main():
         print("Unable to find DM compiler.")
         exit(1)
 
-    code = subprocess.call([compiler, dme])
+    loop = asyncio.get_event_loop()
+    code = loop.run_until_complete(run_compiler([compiler, dme]))
     exit(code)
 
+# DM SOMEHOW manages to go 10 minutes without logging anything nowadays.
+# So... Travis kills it.
+# Thanks DM.
+# This repeats messages like travis_wait (which I couldn't get working) does to prevent that.
+@asyncio.coroutine
+def run_compiler(args):
+    compiler_process = yield from asyncio.create_subprocess_exec(*args)
+    task = ensure_future(print_timeout_guards())
+
+    ret = yield from compiler_process.wait()
+    task.cancel()
+    return ret
+
+@asyncio.coroutine
+def print_timeout_guards():
+    while True:
+        yield from asyncio.sleep(8*60)
+        print("Keeping Travis alive. Ignore this!")
+
 if __name__ == "__main__":
     main()