Add some travis debugging for python scripts

Adds printing to the console before/after calls to bitcoin-cli -rpcwait,
if the PYTHON_DEBUG environment variable is initialized.

.travis.yml

@@ -16,6 +16,7 @@ env:
     - CCACHE_COMPRESS=1
     - BASE_OUTDIR=$TRAVIS_BUILD_DIR/out
     - SDK_URL=https://bitcoincore.org/depends-sources/sdks
+    - PYTHON_DEBUG=1
 cache:
   apt: true
   directories:

qa/rpc-tests/util.py

@@ -88,8 +88,12 @@ def initialize_chain(test_dir):
             if i > 0:
                 args.append("-connect=127.0.0.1:"+str(p2p_port(0)))
             bitcoind_processes[i] = subprocess.Popen(args)
+            if os.getenv("PYTHON_DEBUG", ""):
+                print "initialize_chain: bitcoind started, calling bitcoin-cli -rpcwait getblockcount"
             subprocess.check_call([ os.getenv("BITCOINCLI", "bitcoin-cli"), "-datadir="+datadir,
                                     "-rpcwait", "getblockcount"], stdout=devnull)
+            if os.getenv("PYTHON_DEBUG", ""):
+                print "initialize_chain: bitcoin-cli -rpcwait getblockcount completed"
         devnull.close()
         rpcs = []
         for i in range(4):
@@ -169,9 +173,13 @@ def start_node(i, dirname, extra_args=None, rpchost=None, timewait=None, binary=
     if extra_args is not None: args.extend(extra_args)
     bitcoind_processes[i] = subprocess.Popen(args)
     devnull = open("/dev/null", "w+")
+    if os.getenv("PYTHON_DEBUG", ""):
+        print "start_node: bitcoind started, calling bitcoin-cli -rpcwait getblockcount"
     subprocess.check_call([ os.getenv("BITCOINCLI", "bitcoin-cli"), "-datadir="+datadir] +
                           _rpchost_to_args(rpchost)  +
                           ["-rpcwait", "getblockcount"], stdout=devnull)
+    if os.getenv("PYTHON_DEBUG", ""):
+        print "start_node: calling bitcoin-cli -rpcwait getblockcount returned"
     devnull.close()
     url = "http://rt:rt@%s:%d" % (rpchost or '127.0.0.1', rpc_port(i))
     if timewait is not None: