bitbake: fetch/wget: Add timeout for checkstatus calls (30s)

We had an issue where a webserver serving sstate had filesystem issues so
would accept connections but effectively not do anything with them. This
causes bitbake to hang whilst processing things like sstate objects inside
the checkstatus() calls. It can be replicated by setting up a server like:

socat -u TCP4-LISTEN:NNN,fork OPEN:/dev/null

and pointing SSTATE_MIRRORS in OE at that address.

Adding a timeout to the checkstatus calls of 30s means that whilst the
system will pause, it will then continue and not hang entirely. Since there
isn't a large transfer here, 30s should be a reasonable response time after
which we should fall back to building things ourselves.

[YOCTO #13716]

(Bitbake rev: 92bb53adf47b95182e763a41cd6f4f920250e7b7)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/fetch2/wget.py

@@ -316,7 +316,7 @@ class Wget(FetchMethod):
             except (TypeError, ImportError, IOError, netrc.NetrcParseError):
                 pass
 
-            with opener.open(r) as response:
+            with opener.open(r, timeout=30) as response:
                 pass
         except urllib.error.URLError as e:
             if try_again: