Indefinite build hangs during python tests of gpgme1.0 v1.8

See also Bug #1647204 for full report on gpgme1.0 issues

In the case of LP builds, after setting export DEB_BUILD_MAINT_OPTIONS = hardening=+all,-pie,+pic to allow the builds to find Qt and progress past configure, the resultant build hang indefinitely during their python tests.

Example here: https://launchpad.net/~rikmills/+archive/ubuntu/staging3/+build/11809478

eventually killed by LP due to inactivity.

This hang does not occur when the same sources are built on:

- debian build system/builders
- pbuilder
- standard sbuild
- sbuild created with sbuild-launchpad-chroot
- compiled from source conventionally on a local system

So this appears to be some quirk of the launchpad builder setup/environment itself.

Adding some debug statements on other the builds showed that that hang is occurring in

lang / python / tests / t-callbacks.py

specifically, when the c.op_genkey call is made in the section shown below.

# Test the progress callback.
parms = """<GnupgKeyParms format="internal">
Key-Type: RSA
Key-Length: 1024
Name-Real: Joe Tester
Name-Comment: with stupid passphrase
Name-Email: <email address hidden>
Passphrase: Crypt0R0cks
Expire-Date: 2020-12-31
</GnupgKeyParms>
"""

messages = []
def progress_cb(what, typ, current, total, hook=None):
    assert hook == messages
    messages.append(
        "PROGRESS UPDATE: what = {}, type = {}, current = {}, total = {}"
        .format(what, typ, current, total))

c = gpg.Context()
c.set_progress_cb(progress_cb, messages)
c.op_genkey(parms, None, None) <---- HANGS HERE
assert len(messages) > 0

# Test exception handling.
def progress_cb(what, typ, current, total, hook=None):
    raise myException

c = gpg.Context()
c.set_progress_cb(progress_cb, None)
try:
    c.op_genkey(parms, None, None) <---- HANGS HERE
except Exception as e:
    assert e == myException
else:
    assert False, "Expected an error, got none"