[qa] test_framework: Set wait-timeout for bitcoind procs #8047

Since we switched to python3, it is now possible to set a timeout for Popen.wait(). 60 seconds should be enough to cleanly exit?

Concept ACK, this avoids an infinite wait / travis timeout. What happens if the deadline is not met? Is there a clear exception?

Depends on how you run the tests:

• Running them directly will give you:

subprocess.TimeoutExpired: Command '['bitcoind', '-datadir=/tmp/testh6waqi5c/node0', '-server']' timed out after 60 seconds
$ echo $?
1

• Running them through the wrapper gives:

subprocess.TimeoutExpired: Command '['/home/marco/workspace/bitcoin/qa/rpc-tests/walletbackup.py', '--srcdir=/home/marco/workspace/bitcoin/src', '--portseed=0']' timed out after 3 seconds
$ echo $?
1

Edit: For the wrapper: As there is no traceback printed (of the actual timeout in the python test), one could add a help message to the wrapper saying something like: "Some processes may be still running. Make sure to kill any bitcoind subprocesses before running further tests. To inspect the traceback, run the command mentioned above in the TimeoutExpired Exception from your command line." But I consider this out of scope for this pull.

utACK fab5233

Oops forgot about this utACK https://github.com/bitcoin/bitcoin/pull/8047/commits/fab5233fe6c99d446a2cebc48cf479c3f026c2cc